International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Growth and characterization of cd s doped kdp single crystalseSAT Journals
This document summarizes the growth and characterization of cadmium sulfide (CdS) doped potassium dihydrogen phosphate (KDP) single crystals. Six crystals were grown - pure KDP and KDP doped with varying amounts of CdS nanoparticles. The crystals were characterized through techniques such as X-ray diffraction, infrared spectroscopy, thermal analysis, optical transmission measurements, and electrical measurements. The results indicate that doping with CdS nanoparticles influences the structural, chemical, thermal, optical and electrical properties of KDP crystals.
Growth, structural, optical, electrical and SHG studies of N-N′ allylthiourea...IJERA Editor
Potassium Dihydrogen Phosphate (KDP) crystals are one of the most popular crystals used for Non-linear
Optical (NLO) applications. Pure KDP single crystals and KDP crystals doped with N-N′ allylthiourea were
grown by the method of slow evaporation from aqueous solutions. The grown pure and doped crystals were
confirmed by X-ray single crystal and powder diffraction studies. The pure and doped crystals were
characterized by FTIR spectroscopy studies. Absorptions of these grown crystals were analyzed using UV–Vis–
NIR studies, and it was found that these crystals possess minimum absorption in the entire visible region.
Nonlinear optical studies of pure and doped crystals were carried out and it reveals that the dopants have
increased the efficiency of KDP crystals. Dielectric measurements were carried out along both the unique axis
and perpendicular directions at various temperatures ranging from 40 to 150 °C. The dielectric constant and the
dielectric loss values of N-N′ allylthiourea doped KDP crystals were lower than the pure KDP crystals. Also, it
indicates that 0.8 mole% N-N′ allylthiourea addition to KDP leads to low permittivity value dielectrics. The
results are discussed.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
In recent years, different types of inorganic nanoparticles (iNPs) with unique physicochemical properties have emerged.1−4 Among these, quantum dots (QDs) have proved to be very versatile,finding applications in electroluminescent displays, quantumcomputing, photovoltaics , solar cells,transistors,and biological imaging.For biological imaging applications, QDs are now excellent alternatives to organic chromophores.given that they can have similar sizes, shapes,and surface functional groups. A potentially prolific new direction in inorganic chemistry and nanochemistry could be to combine NPs with small metal complexes to seek synergistic and/or cooperative effects. In this context,combining QDs with coordination complexes is being explored as a new strategy to obtain cooperative systems with improved properties for applications in sensing, biological imaging, and molecular therapy. A prominent area of research in coordination chemistry is the development of metal complexes that can act as artificial nucleases. Overall, these synthetic DNA-cleaving reagents
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Characterization and DC Conductivity of Novel CuO doped Polyvinyl Alcohol (PV...IJERA Editor
The document summarizes research on the characterization and DC conductivity of novel copper oxide (CuO) doped polyvinyl alcohol (PVA) nano-composite films. PVA-CuO composite films with 1-4 wt% CuO were prepared by solution casting. The composites were characterized using XRD, FTIR, SEM, EDXS. XRD showed CuO retained its structure in the composite. FTIR showed interactions between PVA and CuO. DC conductivity increased with temperature, indicating semiconducting behavior. Conductivity increased with higher CuO content, with maximum at 4 wt%. The study analyzed the structural, morphological and electrical properties of the PVA-CuO nano-comp
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Growth and characterization of cd s doped kdp single crystalseSAT Journals
This document summarizes the growth and characterization of cadmium sulfide (CdS) doped potassium dihydrogen phosphate (KDP) single crystals. Six crystals were grown - pure KDP and KDP doped with varying amounts of CdS nanoparticles. The crystals were characterized through techniques such as X-ray diffraction, infrared spectroscopy, thermal analysis, optical transmission measurements, and electrical measurements. The results indicate that doping with CdS nanoparticles influences the structural, chemical, thermal, optical and electrical properties of KDP crystals.
Growth, structural, optical, electrical and SHG studies of N-N′ allylthiourea...IJERA Editor
Potassium Dihydrogen Phosphate (KDP) crystals are one of the most popular crystals used for Non-linear
Optical (NLO) applications. Pure KDP single crystals and KDP crystals doped with N-N′ allylthiourea were
grown by the method of slow evaporation from aqueous solutions. The grown pure and doped crystals were
confirmed by X-ray single crystal and powder diffraction studies. The pure and doped crystals were
characterized by FTIR spectroscopy studies. Absorptions of these grown crystals were analyzed using UV–Vis–
NIR studies, and it was found that these crystals possess minimum absorption in the entire visible region.
Nonlinear optical studies of pure and doped crystals were carried out and it reveals that the dopants have
increased the efficiency of KDP crystals. Dielectric measurements were carried out along both the unique axis
and perpendicular directions at various temperatures ranging from 40 to 150 °C. The dielectric constant and the
dielectric loss values of N-N′ allylthiourea doped KDP crystals were lower than the pure KDP crystals. Also, it
indicates that 0.8 mole% N-N′ allylthiourea addition to KDP leads to low permittivity value dielectrics. The
results are discussed.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
In recent years, different types of inorganic nanoparticles (iNPs) with unique physicochemical properties have emerged.1−4 Among these, quantum dots (QDs) have proved to be very versatile,finding applications in electroluminescent displays, quantumcomputing, photovoltaics , solar cells,transistors,and biological imaging.For biological imaging applications, QDs are now excellent alternatives to organic chromophores.given that they can have similar sizes, shapes,and surface functional groups. A potentially prolific new direction in inorganic chemistry and nanochemistry could be to combine NPs with small metal complexes to seek synergistic and/or cooperative effects. In this context,combining QDs with coordination complexes is being explored as a new strategy to obtain cooperative systems with improved properties for applications in sensing, biological imaging, and molecular therapy. A prominent area of research in coordination chemistry is the development of metal complexes that can act as artificial nucleases. Overall, these synthetic DNA-cleaving reagents
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Characterization and DC Conductivity of Novel CuO doped Polyvinyl Alcohol (PV...IJERA Editor
The document summarizes research on the characterization and DC conductivity of novel copper oxide (CuO) doped polyvinyl alcohol (PVA) nano-composite films. PVA-CuO composite films with 1-4 wt% CuO were prepared by solution casting. The composites were characterized using XRD, FTIR, SEM, EDXS. XRD showed CuO retained its structure in the composite. FTIR showed interactions between PVA and CuO. DC conductivity increased with temperature, indicating semiconducting behavior. Conductivity increased with higher CuO content, with maximum at 4 wt%. The study analyzed the structural, morphological and electrical properties of the PVA-CuO nano-comp
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Investigation on Growth and Optical Properties of LVCC Single CrystalsIJERA Editor
L-valine cadmium chloride (LVCC) single crystals were grown by slow evaporation technique with different
concentrations (0.25, 0.5, 0.75 and 1.0 mole) of CdCl2. All the grown crystals were subjected to single crystal
X-ray diffraction analysis. Solid state parameters were calculated for the grown crystals. The optical properties
of the crystals were investigated by UV-Vis. absorption spectroscopy. The results revealed that, the wider
bandgap and large transparency in the visible region along with higher polarizability of the grown crystals are
highly useful in optoelectronic devices. Also according to our needs, one can tune the optical and electrical
properties of LVCC crystals by adjusting the concentration of CdCl2 in LVCC.
This document summarizes the synthesis and characterization of cadmium sulfide (CdS) nanorods doped with copper (Cu) for application in photonic devices. X-ray diffraction analysis showed that the as-prepared CdS:Cu nanorods were a mixture of hexagonal and cubic phases, with preferential growth of the (100) plane. Transmission electron microscopy images revealed garland-like nanorod structures consisting of cubic and hexagonal particles, with hexagonal particles confirming the hexagonal phase of CdS. The CdS:Cu nanorods exhibited a red shift in absorption compared to undoped CdS, indicating quantum confinement effects due to Cu doping.
The document summarizes a study on the variation in melting point of encapsulated silver nanoparticles with size. Silver nanoparticles were synthesized with inert oxide shells like ZrO2 and SiO2 using chemical methods. Characterization techniques like XRD, SEM, TEM and EDS were used to analyze the structure and composition. Differential thermal and scanning calorimetry were employed to determine the melting transition at different sizes. Samples with silver core sizes of around 12nm and 30nm were prepared using a ZrO2 shell, while SiO2 shell samples were synthesized by varying reaction parameters to obtain silver cores between 2nm to 30nm.
This document summarizes research on cadmium sulfide (CdS) thin films doped with cobalt (Co) prepared using the spray pyrolysis technique. Key findings include:
1. Cd1-xCoxS thin films were deposited on glass substrates at 523K for x=0.00, 0.10, 0.20, and 0.40 compositions.
2. Energy dispersive X-ray analysis confirmed the presence of Cd, S, and Co in the appropriate stoichiometric ratios.
3. X-ray diffraction showed all films were amorphous in nature as deposited.
4. The optical band gap decreased from 2.54 eV to 2.40 eV
OPTICAL BEHAVIOUR OF SYNTHESIZED ZNO NANOTABLETS AND ITS TRANSFORMED NANORODS...antjjournal
We are reporting the preparation of ZnO nanotablets at relatively low temperature (1500C) using zinc acetate [Zn(Ac)2], NaOH, cetyltrimethylammonium bromide (CTAB) by solvothermal method. By adjusting
the molar ratio of the reactants we obtained nanorods and we also obtained the variation of the dimension
of the nanorods using hydrazine hydrate as capping reagent. The prepared samples were morphologically
recognized as well crystallized. The average diameter of the ZnO nanotablets were ranging from 500 to 600 nm and the average thickness of the nanotablets were ranging from 85 to 90 nm. The length of ZnO nanorods were ranging from 300 to several micrometers and breadth of the ZnO nanorods were ranging from 80 to 160 nm. The optical properties of the prepared materials have also been studied with the exhibition of its interesting behavior.
The study investigated the effect of nano-bio interfaces on the genotoxicity of titanium dioxide nanoparticles. It found that the medium which elicited the smallest nanoparticle agglomerates (KF medium containing serum proteins) was associated with the highest cellular uptake, micronuclei formation, and percentage of cells in the S phase of the cell cycle. In contrast, DNA damage occurred regardless of agglomeration or uptake. The results suggest that inhalation exposure may not cause chromosomal damage in lung cells, but ingestion exposing nanoparticles to serum proteins could lower agglomeration and induce micronuclei formation.
Synthesis and application of natural dye sensitizd cds thin films as photoano...eSAT Journals
Abstract
Natural dyes obtained from plants, vegetables and fruits are widely studied and tested as low cost sensitizer for dye sensitized solar cell ( DSSC) in order to replace the rare and expensive inorganic and organic sensitizers. Although, many works have been done using TiO2, ZrO2, ZnO etc. as the nanoporous semiconductor, little importance was given to the use of CdS thin film as a cost effective alternative. In the present study CdS thin films were synthesized by chemical bath deposition (CBD) technique and its optical, structural and morphological properties were investigated by XRD, SEM and UV-Vis absorption spectroscopy. The as synthesized films were found to be nanoporous in nature and are favorable for adsorbing the dyes on to its surface. Two natural dyes extracted from locally available plant leaves namely lawsonia inermis linn and caesalpinia pulcherrima were then adsorbed on the as synthesized CdS thin films for the formation of the working electrode for application in DSSC. The interaction between the nanoporous CdS thin films and the natural dyes were investigated through UV-Vis absorption spectroscopy with an aim to fabricate working electrode for application in DSSC.
Keywords: DSSC, thin film, CdS, natural dyes
1) Tin oxide nanostructures were synthesized via a hydrothermal process to optimize their morphology for use as photoanodes in dye-sensitized solar cells.
2) Samples synthesized at different temperatures resulted in different nanostructure morphologies. The sample synthesized at 200°C showed an optimal mixture of tin oxide nanoparticles and hollow nanospheres.
3) When used as a photoanode, the optimized tin oxide nanostructures synthesized at 200°C achieved the highest photovoltaic conversion efficiency of 7.5%, the highest reported for pristine tin oxide at the time.
Fabrication of zn o nanorod modified ITOViolet Flower
This document discusses the fabrication and characterization of zinc oxide (ZnO) nanorod arrays deposited on indium tin oxide (ITO) glass substrates via chemical bath deposition. Key points:
- ZnO nanorods were grown on ITO-coated glass by immersing the substrates in solutions containing zinc nitrate and hexamethylenetetramine at 80°C for varying times.
- Scanning electron microscopy images showed the diameter of the ZnO nanorods increased with higher solution concentration and longer growth time.
- X-ray diffraction analysis identified the crystal structure of the ZnO nanorods. Electrochemical measurements including cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the electron transfer properties of
Influence of Biofield Treatment on Physical and Structural Characteristics of...albertdivis
Barium oxide (BaO) and zinc sulfide (ZnS) are well known for their applications in electrical, optical and chemical industries. The present study was aimed to evaluate the impact of biofield treatment on the structural and physical properties of BaO and ZnS powder.
Sigma Xi Student Research Showcase Presentationrprasad5
1) The study evaluated the effect of nano-bio interfaces on the genotoxicity of titanium dioxide nanoparticles using different treatment media.
2) The medium that elicited the smallest nanoparticle agglomerates (KF medium containing serum proteins) was associated with the highest cellular uptake, micronuclei formation, and increased percentage of cells in the S phase of the cell cycle.
3) In contrast, DNA damage was induced regardless of agglomeration and cellular uptake. The results suggest that while inhalation exposure may not induce micronuclei in lung cells, ingestion exposing nanoparticles to serum proteins could lower agglomeration and induce micronuclei formation.
Crystal Growth and Studies of Dihydrogen Phosphates of Potassium and Ammonium...IJERA Editor
A nonlinear optical (NLO) material Potassium dihydrogen phosphates (KDP) and Ammonium dihydrogen
phosphates (ADP) are grown by slow evaporation solution growth technique. The FTIR studies confirm the
presence of the functional group in the grown crystal. The optical transmittance studies show that the crystal has
transparence in the entire visible and IR region. The thermal stability of the materials was assessed by TG/DTA
analysis. The mechanical stability of the grown crystals was analyzed by Vicker’s microhardness test. The
dielectric behavior of the crystals was tested by dielectric analysis. The second harmonic generation (SHG) of
KDP is confirmed by Kurtz and Perry powder technique using Nd: YAG laser.
Hydrothermal synthesis and characterization of oneAlexander Decker
The document summarizes research on synthesizing and characterizing one-dimensional ceria nanorods for removing chromium ions from wastewater. Key points:
1) Ceria nanorods were synthesized via a hydrothermal method and characterized using techniques like SEM, TEM, XRD, and BET surface area analysis.
2) The ceria nanorods were 20-40nm in diameter and 200-300nm in length and had a high surface area of 78 m2/g, making them promising for chromium removal.
3) X-ray absorption spectroscopy (XAS) was used to investigate the oxidation states and local structure of ceria nanorods to better understand the surface reaction during chromium removal.
Mechanical Properties of Concrete with Marine Sand as Partial Replacement of ...IJERA Editor
The process of depleting sources of natural aggregates challenges the production of technically and
environmentally adequate concrete. Alternative material from marine sources is good enough for the
replacement of fine aggregate in the concrete. The material was stockpiled in the open air and no washing,
drying or decontamination process was carried out. Physical and chemical properties of DMS material were
determined. All the materials used in the concrete were selected and tested as per the standard procedures of the
Indian standards. A unique design mix will be done based on the entire material test results. Different mixtures
were produced using DMS in different proportions from 15% to 100% as per the finalized trial of the design
mix. The concrete were submitted to compressive strength testsafter 7, 28 and 90 days of moist curing, as well
as flexure and splitting tensile strength tests for M-25 grade.
Vineet Jagadeesan Nair designed and tested dye-sensitized solar cells using novel organic dye sensitizers to improve power conversion efficiency and long-term stability. Through co-sensitization techniques and material optimizations, a champion efficiency of over 9% was achieved. Organic dyes offer advantages over traditional ruthenium-based dyes such as lower cost and easier synthesis, but have disadvantages including weaker light absorption and shorter exciton lifetimes. Co-sensitization of dyes with complementary absorption spectra can improve overall light harvesting.
Effect of Co Dopant on Structure and DC Conductivity of Sn1-XCoxO2 Nanoparticlespaperpublications3
The document describes a study on the effect of cobalt (Co) doping on the structure and electrical conductivity of tin oxide (SnO2) nanoparticles. Sn1-xCoxO2 nanoparticles were synthesized by a gel combustion method with varying Co concentration (x=0, 0.01, 0.02, 0.03, 0.04). X-ray diffraction analysis confirmed the nanoparticles had a tetragonal rutile structure and crystallite size decreased with increasing Co content. Scanning electron microscopy showed the nanoparticles were spherical in shape and agglomerated. Electrical conductivity increased with temperature but decreased with higher Co concentration, indicating fewer free charge carriers due to Co doping. The activation energy for conduction also increased with decreasing
The document describes the synthesis and characterization of CeO2 and Ni-doped CeO2 spherical nanoparticles for magnetic and electrochemical applications. CeO2 and Ni-doped CeO2 with 1%, 3%, 5%, and 7% Ni were prepared via a microwave-assisted method and characterized. Thermogravimetric analysis showed the Ni-doping enhanced the thermal stability of CeO2. X-ray diffraction and Raman spectroscopy confirmed the formation of cubic fluorite CeO2 and showed the introduction of defects with Ni-doping. Electrochemical tests revealed the 5% Ni-doped CeO2 sample had the highest specific capacitance of 577 F g-1 and maintained 94% capacitance
Dielectric properties of pure and ni2+ doped glycine sodium sulfate crystalseSAT Journals
Abstract Pure and Ni2+ added glycine sodium sulfate (GSS) single crystals were grown by the slow evaporation technique and characterized chemically, structurally, thermally, optically, mechanically and electrically. Effect of Ni2+ addition as an impurity on the properties of GSS has also been investigated. All the six crystals grown exhibit normal dielectric behavior and are found to be thermally stable up to 250˚C, NLO active and mechanically soft. The Ni2+ addition is found to increase the dielectric parameters. The low dielectric constant values observed for pure GSS indicate that GSS is not only a promising NLO material but also a low dielectric constant value dielectric material. Keywords: Activation energy, Crystal growth, Dielectric crystal, Electrical properties, X-ray diffraction
The document summarizes different methods for synthesizing cadmium sulfide (CdS) nanoparticles. It describes an aqueous precipitation method using cadmium nitrate and sodium sulfide precursors that produces yellow CdS precipitate. It also outlines a sol-gel method using cadmium acetate, diaminobenzene, and thioacetamide precursors that generates a CdS sol and gel. Additionally, it mentions a hydrothermal method using cadmium nitrate, thiourea, and hexamethylenetetramine precursors under high temperature and pressure that can control CdS morphology. The document provides an overview of various preparation techniques for CdS nanoparticles.
Optimal growth and characterization of cobalt sulphide thin films fabricated ...Alexander Decker
The document summarizes research on growing and characterizing cobalt sulfide thin films using chemical bath deposition. Key findings include:
1) Cobalt sulfide thin films were successfully deposited on glass from an aqueous solution containing cobalt chloride, thiourea, ammonia, and EDTA.
2) The films showed high absorbance of UV light and low transmittance in the UV region, indicating they could be used in applications requiring UV filtering.
3) Band gap energy of the films was found to be 1.72 eV, making the material suitable for photovoltaic and optoelectronic devices.
The document summarizes a study that tested the lateral load resistance of plastered-bamboo walls with different bracing configurations. Three wall configurations were tested: 1) without bracing (DP-TB), 2) with bamboo bracing (DP-BB), and 3) with wiremesh bracing (DP-BK). Monotonic loading tests found that DP-BK had the highest peak load capacity, energy dissipation, and ductility. However, DP-BB had the highest elastic stiffness. Failure mechanisms also differed, with DP-TB experiencing joint dislodging, DP-BB experiencing shear and bending failure, and DP-BK experiencing bending failure.
This document discusses the design of an off-grid home energy system using solar, wind, and biomass energy sources. It first provides background on the need for renewable energy systems in remote areas. It then describes the components of the hybrid system, including photovoltaic panels, a wind turbine, and a biomass generator. The document outlines how Homer software was used to simulate and optimize different configurations to determine the most cost-effective system. The simulation analyzed factors like solar radiation levels, wind speeds, and biomass availability to predict the hybrid system's performance.
Investigation on Growth and Optical Properties of LVCC Single CrystalsIJERA Editor
L-valine cadmium chloride (LVCC) single crystals were grown by slow evaporation technique with different
concentrations (0.25, 0.5, 0.75 and 1.0 mole) of CdCl2. All the grown crystals were subjected to single crystal
X-ray diffraction analysis. Solid state parameters were calculated for the grown crystals. The optical properties
of the crystals were investigated by UV-Vis. absorption spectroscopy. The results revealed that, the wider
bandgap and large transparency in the visible region along with higher polarizability of the grown crystals are
highly useful in optoelectronic devices. Also according to our needs, one can tune the optical and electrical
properties of LVCC crystals by adjusting the concentration of CdCl2 in LVCC.
This document summarizes the synthesis and characterization of cadmium sulfide (CdS) nanorods doped with copper (Cu) for application in photonic devices. X-ray diffraction analysis showed that the as-prepared CdS:Cu nanorods were a mixture of hexagonal and cubic phases, with preferential growth of the (100) plane. Transmission electron microscopy images revealed garland-like nanorod structures consisting of cubic and hexagonal particles, with hexagonal particles confirming the hexagonal phase of CdS. The CdS:Cu nanorods exhibited a red shift in absorption compared to undoped CdS, indicating quantum confinement effects due to Cu doping.
The document summarizes a study on the variation in melting point of encapsulated silver nanoparticles with size. Silver nanoparticles were synthesized with inert oxide shells like ZrO2 and SiO2 using chemical methods. Characterization techniques like XRD, SEM, TEM and EDS were used to analyze the structure and composition. Differential thermal and scanning calorimetry were employed to determine the melting transition at different sizes. Samples with silver core sizes of around 12nm and 30nm were prepared using a ZrO2 shell, while SiO2 shell samples were synthesized by varying reaction parameters to obtain silver cores between 2nm to 30nm.
This document summarizes research on cadmium sulfide (CdS) thin films doped with cobalt (Co) prepared using the spray pyrolysis technique. Key findings include:
1. Cd1-xCoxS thin films were deposited on glass substrates at 523K for x=0.00, 0.10, 0.20, and 0.40 compositions.
2. Energy dispersive X-ray analysis confirmed the presence of Cd, S, and Co in the appropriate stoichiometric ratios.
3. X-ray diffraction showed all films were amorphous in nature as deposited.
4. The optical band gap decreased from 2.54 eV to 2.40 eV
OPTICAL BEHAVIOUR OF SYNTHESIZED ZNO NANOTABLETS AND ITS TRANSFORMED NANORODS...antjjournal
We are reporting the preparation of ZnO nanotablets at relatively low temperature (1500C) using zinc acetate [Zn(Ac)2], NaOH, cetyltrimethylammonium bromide (CTAB) by solvothermal method. By adjusting
the molar ratio of the reactants we obtained nanorods and we also obtained the variation of the dimension
of the nanorods using hydrazine hydrate as capping reagent. The prepared samples were morphologically
recognized as well crystallized. The average diameter of the ZnO nanotablets were ranging from 500 to 600 nm and the average thickness of the nanotablets were ranging from 85 to 90 nm. The length of ZnO nanorods were ranging from 300 to several micrometers and breadth of the ZnO nanorods were ranging from 80 to 160 nm. The optical properties of the prepared materials have also been studied with the exhibition of its interesting behavior.
The study investigated the effect of nano-bio interfaces on the genotoxicity of titanium dioxide nanoparticles. It found that the medium which elicited the smallest nanoparticle agglomerates (KF medium containing serum proteins) was associated with the highest cellular uptake, micronuclei formation, and percentage of cells in the S phase of the cell cycle. In contrast, DNA damage occurred regardless of agglomeration or uptake. The results suggest that inhalation exposure may not cause chromosomal damage in lung cells, but ingestion exposing nanoparticles to serum proteins could lower agglomeration and induce micronuclei formation.
Synthesis and application of natural dye sensitizd cds thin films as photoano...eSAT Journals
Abstract
Natural dyes obtained from plants, vegetables and fruits are widely studied and tested as low cost sensitizer for dye sensitized solar cell ( DSSC) in order to replace the rare and expensive inorganic and organic sensitizers. Although, many works have been done using TiO2, ZrO2, ZnO etc. as the nanoporous semiconductor, little importance was given to the use of CdS thin film as a cost effective alternative. In the present study CdS thin films were synthesized by chemical bath deposition (CBD) technique and its optical, structural and morphological properties were investigated by XRD, SEM and UV-Vis absorption spectroscopy. The as synthesized films were found to be nanoporous in nature and are favorable for adsorbing the dyes on to its surface. Two natural dyes extracted from locally available plant leaves namely lawsonia inermis linn and caesalpinia pulcherrima were then adsorbed on the as synthesized CdS thin films for the formation of the working electrode for application in DSSC. The interaction between the nanoporous CdS thin films and the natural dyes were investigated through UV-Vis absorption spectroscopy with an aim to fabricate working electrode for application in DSSC.
Keywords: DSSC, thin film, CdS, natural dyes
1) Tin oxide nanostructures were synthesized via a hydrothermal process to optimize their morphology for use as photoanodes in dye-sensitized solar cells.
2) Samples synthesized at different temperatures resulted in different nanostructure morphologies. The sample synthesized at 200°C showed an optimal mixture of tin oxide nanoparticles and hollow nanospheres.
3) When used as a photoanode, the optimized tin oxide nanostructures synthesized at 200°C achieved the highest photovoltaic conversion efficiency of 7.5%, the highest reported for pristine tin oxide at the time.
Fabrication of zn o nanorod modified ITOViolet Flower
This document discusses the fabrication and characterization of zinc oxide (ZnO) nanorod arrays deposited on indium tin oxide (ITO) glass substrates via chemical bath deposition. Key points:
- ZnO nanorods were grown on ITO-coated glass by immersing the substrates in solutions containing zinc nitrate and hexamethylenetetramine at 80°C for varying times.
- Scanning electron microscopy images showed the diameter of the ZnO nanorods increased with higher solution concentration and longer growth time.
- X-ray diffraction analysis identified the crystal structure of the ZnO nanorods. Electrochemical measurements including cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the electron transfer properties of
Influence of Biofield Treatment on Physical and Structural Characteristics of...albertdivis
Barium oxide (BaO) and zinc sulfide (ZnS) are well known for their applications in electrical, optical and chemical industries. The present study was aimed to evaluate the impact of biofield treatment on the structural and physical properties of BaO and ZnS powder.
Sigma Xi Student Research Showcase Presentationrprasad5
1) The study evaluated the effect of nano-bio interfaces on the genotoxicity of titanium dioxide nanoparticles using different treatment media.
2) The medium that elicited the smallest nanoparticle agglomerates (KF medium containing serum proteins) was associated with the highest cellular uptake, micronuclei formation, and increased percentage of cells in the S phase of the cell cycle.
3) In contrast, DNA damage was induced regardless of agglomeration and cellular uptake. The results suggest that while inhalation exposure may not induce micronuclei in lung cells, ingestion exposing nanoparticles to serum proteins could lower agglomeration and induce micronuclei formation.
Crystal Growth and Studies of Dihydrogen Phosphates of Potassium and Ammonium...IJERA Editor
A nonlinear optical (NLO) material Potassium dihydrogen phosphates (KDP) and Ammonium dihydrogen
phosphates (ADP) are grown by slow evaporation solution growth technique. The FTIR studies confirm the
presence of the functional group in the grown crystal. The optical transmittance studies show that the crystal has
transparence in the entire visible and IR region. The thermal stability of the materials was assessed by TG/DTA
analysis. The mechanical stability of the grown crystals was analyzed by Vicker’s microhardness test. The
dielectric behavior of the crystals was tested by dielectric analysis. The second harmonic generation (SHG) of
KDP is confirmed by Kurtz and Perry powder technique using Nd: YAG laser.
Hydrothermal synthesis and characterization of oneAlexander Decker
The document summarizes research on synthesizing and characterizing one-dimensional ceria nanorods for removing chromium ions from wastewater. Key points:
1) Ceria nanorods were synthesized via a hydrothermal method and characterized using techniques like SEM, TEM, XRD, and BET surface area analysis.
2) The ceria nanorods were 20-40nm in diameter and 200-300nm in length and had a high surface area of 78 m2/g, making them promising for chromium removal.
3) X-ray absorption spectroscopy (XAS) was used to investigate the oxidation states and local structure of ceria nanorods to better understand the surface reaction during chromium removal.
Mechanical Properties of Concrete with Marine Sand as Partial Replacement of ...IJERA Editor
The process of depleting sources of natural aggregates challenges the production of technically and
environmentally adequate concrete. Alternative material from marine sources is good enough for the
replacement of fine aggregate in the concrete. The material was stockpiled in the open air and no washing,
drying or decontamination process was carried out. Physical and chemical properties of DMS material were
determined. All the materials used in the concrete were selected and tested as per the standard procedures of the
Indian standards. A unique design mix will be done based on the entire material test results. Different mixtures
were produced using DMS in different proportions from 15% to 100% as per the finalized trial of the design
mix. The concrete were submitted to compressive strength testsafter 7, 28 and 90 days of moist curing, as well
as flexure and splitting tensile strength tests for M-25 grade.
Vineet Jagadeesan Nair designed and tested dye-sensitized solar cells using novel organic dye sensitizers to improve power conversion efficiency and long-term stability. Through co-sensitization techniques and material optimizations, a champion efficiency of over 9% was achieved. Organic dyes offer advantages over traditional ruthenium-based dyes such as lower cost and easier synthesis, but have disadvantages including weaker light absorption and shorter exciton lifetimes. Co-sensitization of dyes with complementary absorption spectra can improve overall light harvesting.
Effect of Co Dopant on Structure and DC Conductivity of Sn1-XCoxO2 Nanoparticlespaperpublications3
The document describes a study on the effect of cobalt (Co) doping on the structure and electrical conductivity of tin oxide (SnO2) nanoparticles. Sn1-xCoxO2 nanoparticles were synthesized by a gel combustion method with varying Co concentration (x=0, 0.01, 0.02, 0.03, 0.04). X-ray diffraction analysis confirmed the nanoparticles had a tetragonal rutile structure and crystallite size decreased with increasing Co content. Scanning electron microscopy showed the nanoparticles were spherical in shape and agglomerated. Electrical conductivity increased with temperature but decreased with higher Co concentration, indicating fewer free charge carriers due to Co doping. The activation energy for conduction also increased with decreasing
The document describes the synthesis and characterization of CeO2 and Ni-doped CeO2 spherical nanoparticles for magnetic and electrochemical applications. CeO2 and Ni-doped CeO2 with 1%, 3%, 5%, and 7% Ni were prepared via a microwave-assisted method and characterized. Thermogravimetric analysis showed the Ni-doping enhanced the thermal stability of CeO2. X-ray diffraction and Raman spectroscopy confirmed the formation of cubic fluorite CeO2 and showed the introduction of defects with Ni-doping. Electrochemical tests revealed the 5% Ni-doped CeO2 sample had the highest specific capacitance of 577 F g-1 and maintained 94% capacitance
Dielectric properties of pure and ni2+ doped glycine sodium sulfate crystalseSAT Journals
Abstract Pure and Ni2+ added glycine sodium sulfate (GSS) single crystals were grown by the slow evaporation technique and characterized chemically, structurally, thermally, optically, mechanically and electrically. Effect of Ni2+ addition as an impurity on the properties of GSS has also been investigated. All the six crystals grown exhibit normal dielectric behavior and are found to be thermally stable up to 250˚C, NLO active and mechanically soft. The Ni2+ addition is found to increase the dielectric parameters. The low dielectric constant values observed for pure GSS indicate that GSS is not only a promising NLO material but also a low dielectric constant value dielectric material. Keywords: Activation energy, Crystal growth, Dielectric crystal, Electrical properties, X-ray diffraction
The document summarizes different methods for synthesizing cadmium sulfide (CdS) nanoparticles. It describes an aqueous precipitation method using cadmium nitrate and sodium sulfide precursors that produces yellow CdS precipitate. It also outlines a sol-gel method using cadmium acetate, diaminobenzene, and thioacetamide precursors that generates a CdS sol and gel. Additionally, it mentions a hydrothermal method using cadmium nitrate, thiourea, and hexamethylenetetramine precursors under high temperature and pressure that can control CdS morphology. The document provides an overview of various preparation techniques for CdS nanoparticles.
Optimal growth and characterization of cobalt sulphide thin films fabricated ...Alexander Decker
The document summarizes research on growing and characterizing cobalt sulfide thin films using chemical bath deposition. Key findings include:
1) Cobalt sulfide thin films were successfully deposited on glass from an aqueous solution containing cobalt chloride, thiourea, ammonia, and EDTA.
2) The films showed high absorbance of UV light and low transmittance in the UV region, indicating they could be used in applications requiring UV filtering.
3) Band gap energy of the films was found to be 1.72 eV, making the material suitable for photovoltaic and optoelectronic devices.
The document summarizes a study that tested the lateral load resistance of plastered-bamboo walls with different bracing configurations. Three wall configurations were tested: 1) without bracing (DP-TB), 2) with bamboo bracing (DP-BB), and 3) with wiremesh bracing (DP-BK). Monotonic loading tests found that DP-BK had the highest peak load capacity, energy dissipation, and ductility. However, DP-BB had the highest elastic stiffness. Failure mechanisms also differed, with DP-TB experiencing joint dislodging, DP-BB experiencing shear and bending failure, and DP-BK experiencing bending failure.
This document discusses the design of an off-grid home energy system using solar, wind, and biomass energy sources. It first provides background on the need for renewable energy systems in remote areas. It then describes the components of the hybrid system, including photovoltaic panels, a wind turbine, and a biomass generator. The document outlines how Homer software was used to simulate and optimize different configurations to determine the most cost-effective system. The simulation analyzed factors like solar radiation levels, wind speeds, and biomass availability to predict the hybrid system's performance.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
O documento fornece instruções em 4 passos para acessar a Comunidade Jovem SUS pela primeira vez: 1) Entrar no site, 2) Criar um cadastro usando o CPF, 3) Verificar o e-mail para confirmar o cadastro, 4) Inscrever-se na comunidade digitando a região.
Este documento describe dos platillos típicos de la comida china: fideo frito, que contiene cebolla y carne, y chiquito bollo, que es un desayuno común y también sabroso.
1) Sandra Kaffka trabalhou em projetos de arte pública e curadoria em diversas unidades do SESC, incluindo exposições de artistas brasileiros e internacionais.
2) Nos últimos anos, ela se concentrou em projetos no SESC Ipiranga e SESC Pinheiros, como intervenções urbanas, mostras temáticas e ocupações de espaços não convencionais.
3) Kaffka também esteve envolvida na produção de grandes exposições internacionais, como a individual de Marina Abramović no SESC Pompéia.
Boulevard mode Nova Apresentação de Outubro AtualizadoAdriano-jose
1) O documento apresenta o plano de marketing de uma empresa de cosméticos chamada Boulevard Monde, com detalhes sobre os produtos, oportunidades de negócio e plano de carreira.
2) Os consultores podem ganhar bônus por vendas, indicação de novos consultores, equilíbrio entre equipes e atingimento de metas de carreira.
3) Há diferentes níveis de qualificação que oferecem maiores benefícios conforme o consultor progride.
La autora Luisa Millan presenta un trabajo para la asignatura de Propaganda en la Escuela de Comunicación Social de la Facultad de Ciencias Sociales y Económicas de la Universidad Fermín Toro.
Alteracao na producao de hormonio de crescimento e tireoideUniversidade Lurio
A alteracao na producao da hormona de crescimento e tireoide, causa varios problemas ao nivel do organismo. No caso da hormona de crescimento esta pode impedir o desenvolvimento de todas as celulas, causando varias doencas.
O FAST é um tecnologia única no mundo com equipamentos mecânicos e eletromecânicos em 3D onde podemos montá-los, desmontá-los e etc. O objetivo é atingir as instituições de ensino técnico e superior, empresas e indústrias.
Hh31 08 15 gravidez na adolescência e doenças sexualmente transmissíveiseduvania
O documento discute os desafios da gravidez na adolescência, incluindo a falta de conselhos dos pais e o alto risco de depressão pós-parto. A maioria dos partos de adolescentes são cesarianos devido à dificuldade em fazer força para um parto normal, embora algumas optem por partos naturais.
Este documento resume los principios y orientaciones del Plan de Estudios 2011 de la Escuela Normal de Atizapán de Zaragoza. Describe 12 principios pedagógicos como centrarse en los estudiantes, planificar para potenciar el aprendizaje, y generar ambientes de aprendizaje. También cubre las competencias para la vida, los campos formativos, y cómo se basa en teorías del aprendizaje como el constructivismo.
Esta palestra apresenta dados sobre a pesquisa clinica a nível internacional, faz um resumo sobre a legislação europeia em matéria de ensaios clínicos, e estabelece os motivos que mudaram esta legislação para fazer mais atraente a pesquisa clínica na Europa. Também inclui um resumo sobre o novo Regulamento Europeu de Ensaios Clínicos, com as suas principais novidades e implicações.
1) This document discusses 10X Genomics' linked read technology and its ability to improve genome assembly and variant calling compared to standard short read sequencing.
2) The linked read data from 10X Genomics can correctly place short reads into paralogous loci, improving genome alignment. This leads to improved variant calling compared to standard short read data.
3) Novel variants called from 10X Genomics data and validated using PacBio long reads showed higher validation rates compared to variants called from standard short read data. The document proposes further validation of the variant validation method.
Em 'O matrimônio perfeito' o grande Mestre gnóstico do século XX, Samael Aun Weor, revela a síntese de todas as autênticas religiões, escolas, ordens e seitas: o Cristo e o Sexo. Nesta importante e revolucionária obra são desvendados os grandes segredos ocultos em todas as autênticas tradições, e dadas as chaves para a regeneração espiritual do ser humano.
Este documento presenta un taller grupal sobre la creación de instrumentos de evaluación basados en procedimientos de observación y rendimiento. El grupo debe crear una prueba escrita evaluando conceptos y procedimientos sobre evaluación educativa, y dos copias, una con las preguntas y otra con las respuestas y criterios de corrección.
The document discusses sustainable energy sources and nanomaterials for sustainable development applications. It provides an overview of solar energy and chalcogenide-based solar cells. Research on developing nanostructured metal-doped chalcogenides and tellurides for multifunctional applications such as solar cells and optical/electrical devices is summarized. Synthesis methods for producing semiconductor nanocrystals and nanosheets are described. Characterization shows the materials have tunable properties like optical bandgap dependent on size, composition and doping.
Effect of glycine as an impurity on the properties of Epsomite single crystalsIOSR Journals
Epsomite (MgSO4.7H2O) is a hydrogen bonded crystal having a wide range of applications in various fields. Pure and glycine added Epsomite (a total of six) single crystals have been grown and characterized in order to investigate the effect of glycine as an impurity on the properties of Epsomite crystals.The densities and lattice parameters observed indicate that the impurity molecules have entered into the crystal matrix. The grown crystals exhibit good optical transparency in the wavelength range 210-1100 nm. Second harmonic generation measurements indicate that they are nonlinear optically active. Results obtained through microhardness measurements follow the normal indentation size effect. Electrical (AC and DC) measurements indicate that all the six crystals grown in the present study exhibit a normal dielectric behavior and the electrical conduction is understood to be due to the protonic movement. Moreover, glycine addition is found to reduce εr value significantly indicating the possibility of Epsomite crystal becoming a low -εr value dielectric material.
Nano Tailoring of MnO2 Doped Multiwalled Carbon Nanotubes as Electrode Materi...IRJET Journal
This document describes research on synthesizing manganese dioxide (MnO2) decorated multiwalled carbon nanotubes (MCNT) for use as an electrode material in supercapacitors. MnO2/MCNT nanocomposites were prepared through a simple solvo thermal method. Characterization of the materials was done using XRD, FESEM, TEM, EDS, UV-visible spectroscopy, FTIR, and Raman spectroscopy. The analyses revealed a porous, hierarchical structure of MnO2 coated on the MCNT surface. Increasing the annealing temperature improved the crystallinity and reduced the band gap of the MnO2/MCNT nanocomposite. The synthesized nanocomposite showed potential for high performance
Formation and Characterization of Mixed Crystals Based on Bis (Thiourea)Cadmi...IJERA Editor
Bis(thiourea)cadmium chloride(BTCC) and bis(thiourea)cadmium iodide (BTCI) are metal complexes of thiourea having better nonlinear optical properties than KH2PO4. An attempt has been made in the present study to form mixed crystals based on BTCC and BTCI (even though their crystal lattices mismatch) from aqueous solutions, the precursors mixed in proper proportions. A total of seven (including the end members) crystals were formed by the free evaporation method and characterized chemically, structurally, thermally, optically and electrically. The X-ray diffraction measurements indicate that (BTCC)X(BTCI)1-X crystals with x=1.0,0.8 and 0.6 are orthorhombic in structure with space group Pmn21 and that with x=0.5, 0.4, 0.2 and 0.0 are monoclinic in structure with space group P21/c. All the grown crystals are found to be thermally stable up to 215 °C and possessing wide optical transmission window (300-900 nm) which is suitable for NLO applications. The electrical measurements indicate that the grown crystals exhibit a normal dielectric behavior. The results obtained in the present study indicate that mixed crystals can be formed from the isomorphous precursors directly even though the end member’s crystals have lattice mismatching.
Simple and direct synthesis of zinc vanadate ZnV2O5 nanocrystals for its elec...Arvind Singh Heer
Zinc Vanadate (ZnV2O5) Nanocrystals were prepared by two steps, ceramic route process. Optimization of the
ceramic route processing conditions enhances the Electrocatalytic and Antimicrobial performance of the prepared
nanoparticles. The thermally treated material was subjected to XRD, FTIR, UV-Visible spectroscopy, SEM and
EDS, which confirmed the formation of Zinc Vanadate (ZnV2O5) Nanocrystals. The electrochemical detection of
Anthracene by Zinc Vanadate nanoparticles was investigated by Cyclic Voltammetry. The result concludes that the
ZnV2O5 NPs have the higher activity for detection and oxidation of Anthracene. The as-synthesized ZnV2O5 NPs were
found to exhibit strong antimicrobial activity against both Escherichia coli (E.coli) gram-negative and
Staphylococcus aureus (S. aureus) gram-positive microorganisms implying their strong potential as the antimicrobial
agent.
Synthesis and Characterization of Mn, Ce Co-Doped CDS Nanoparticles Synthesiz...IJMER
Mn, Ce co-doped CdS nanoparticles were prepared by chemical co-precipitation method at room temperature. The prepared samples were characterized by X- ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), photoluminescence (PL) and
high resolution Raman spectroscopic techniques. X-ray diffraction studies showed that the diameter of the particles was around 10-12 nm. Broadened XRD peaks revealed the formation of nanoparticles with wurtzite structure. The Raman spectra of undoped and Mn, Ce ions co-doped CdS nanoparticles showed longitudinal optical mode. Compared with the 1LO and 2LO Raman modes (296 and 590 cm-1
) of undoped CdS nanoparticles, the Raman modes of Mn, Ce co- doped CdS nanoparticles were slightly shifted towards lower frequency. PL spectra of the samples showed remarkable enhancement in the intensity upon doping
Water-splitting photoelectrodes consisting of heterojunctions of carbon nitri...Pawan Kumar
Quinary and senary non-stoichiometric double perovskites such as Ba2Ca0.66Nb1.34−xFexO6−δ (BCNF) have been utilized for gas sensing, solid oxide fuel cells and thermochemical CO2 reduction. Herein, we examined their potential as narrow bandgap semiconductors for use in solar energy harvesting. A cobalt co-doped BCNF, Ba2Ca0.66Nb0.68Fe0.33Co0.33O6−δ (BCNFCo), exhibited an optical absorption edge at ∼800 nm, p-type conduction and a distinct photoresponse up to 640 nm while demonstrating high thermochemical stability. A nanocomposite of BCNFCo and g-C3N4 (CN) was prepared via a facile solvent-assisted exfoliation/blending approach using dichlorobenzene and glycerol at a moderate temperature. The exfoliation of g-C3N4 followed by wrapping on perovskite established an effective heterojunction between the materials for charge separation. The conjugated 2D sheets of CN enabled better charge migration resulting in increased photoelectrochemical performance. A blend composed of 40 wt% perovskites and CN performed optimally, whilst achieving a photocurrent density as high as 1.5 mA cm−2 for sunlight-driven water-splitting with a Faradaic efficiency as high as ∼88%.
Nitrogen-Enriched Carbon Nanobubbles and Nanospheres for Applications in Ener...Devika Laishram
Multifunctional carbon nanomaterials have attracted remarkable consideration for use in various energy
conversion and storage devices because of their ultrahigh specific
surface area, unique morphology, and excellent electrochemical
properties. Herein, we report the synthesis of highly uniform and
ordered nitrogen-enriched carbon nanospheres (CS) and nanobubbles (CNB) by a modified Stöber reaction using resorcinol and
formaldehyde in the presence of ethylenediamine as a nitrogen
source. A comparative study of the prepared CS and CNB
nanomaterials is presented here with potential use in a wide variety
of applications involving large surface area and electrical
conductivity. As counter electrode materials in solar cells, CNB and CS showed enhanced photoelectrochemical activity for
catalytically reducing I3
− to I− and improved capacitive behavior with a low charge transfer resistance and remarkable power
conversion efficiency (PCE) of 10.40% with improved Jsc (20.20 mA/cm2
) and Voc (0.73 V). The enhanced performance of the
fabricated photoelectrochemical cell is due to the excellent point contact and good conductivity that offered better charge
transportation of electrons with minimum recombination. The enhanced adsorption upon increasing the pressure without an
apparent saturation level signified the large CO2 adsorption with 2 mmol/g for the CS. Additionally, the rectangular-shaped CV
curve indicated the double-layer capacitive behavior, good electrochemical reversibility, and high-power characteristics, prerequisites
for supercapacitor application. This study probes the practical possibility of nitrogen-enriched carbon nanostructures as a
multifunctional material for prospective applications.
IRJET - Comparative Study on the Structural and Optical Characterization of Z...IRJET Journal
This document reports on a comparative study of the structural and optical characterization of zinc sulfide (ZnS) and zinc oxide (ZnO) nanoparticles. ZnS nanoparticles were prepared via chemical precipitation using zinc chloride, sodium sulfide, and mercaptoethanol as a capping agent. ZnO nanoparticles were prepared using zinc acetate, ammonia, and thiourea as a capping agent. X-ray diffraction and scanning electron microscopy were used to characterize particle size and structure. Absorption spectra showed a blue shift with decreasing particle size due to quantum confinement. Photoluminescence spectra were also studied. The results show ZnS particles were 2-7nm and ZnO particles were 50-60nm. Both
Synthesis, Characterization of ZnS nanoparticles by Coprecipitation method us...IOSR Journals
ZnS nanoparticles are prepared by coprecipitation method using various capping agents like PVP (polyvinylpyrrolidone), PVA (polyvinylalcohol) and PEG-4000 (polyethyleneglycol). These are characterized by UV-Visible spectra, X-ray diffraction (XRD) studies, Fourier Transform Infra-red spectra (FTIR) and Transmission electron microscopy (TEM). UV-Visible absorption spectra are used to find the optical band gap and the values obtained have been found to be in the range of 3.80-4.00eV. The particle size of nanoparticles calculated from XRD pattern has been in the range of 2-4 nm. It is also observed that the particle size of nanoparticle is affected by the nature of capping agent. Photo catalytic degradation of xylenol orange (XO) by the nanoparticles shows that these act as photo catalysts under sunlight irradiation. The XO dye was degraded more than 87.24, 83.42 and 73.05% in the presence of PEG-4000, PVA and PVP capped ZnS nanoparticles in 120, 150 and 180 min. respectively. The kinetics of catalyzed by synthesized ZnS nanoparticles with XO dye follows pseudo-first order kinetics with reasonable apparent rate constants.
Dye Sensitized Solar Cells Incorporated with Tio2 -ZnO NanoparticlesScientific Review SR
This document summarizes a study that incorporated zinc oxide (ZnO) nanoparticles into dye-sensitized solar cells (DSSCs) to improve their photovoltaic performance. DSSCs were fabricated with TiO2 films that were coated with different numbers of ZnO layers using successive ionic layer adsorption and reaction (SILAR). The cells were tested under illumination and the best performance was achieved with two SILAR cycles of ZnO, with a power conversion efficiency of 0.0064%, over double that of cells without ZnO. More ZnO layers led to lower efficiencies due to increased recombination and reduced light absorption, showing an optimal thickness was achieved with two SILAR cycles.
Water-splitting photoelectrodes consisting of heterojunctions of carbon nitri...Devika Laishram
Quinary and senary non-stoichiometric double perovskites such as Ba2Ca0.66Nb1.34−xFexO6−δ
(BCNF) have been utilized for gas sensing, solid oxide fuel cells and thermochemical CO2
reduction. Herein, we examined their potential as narrow bandgap semiconductors for use in solar
energy harvesting. A cobalt co-doped BCNF, Ba2Ca0.66Nb0.68Fe0.33Co0.33O6−δ (BCNFCo),
exhibited an optical absorption edge at ∼800 nm, p-type conduction and a distinct photoresponse
up to 640 nm while demonstrating high thermochemical stability. A nanocomposite of BCNFCo
and g-C3N4 (CN) was prepared via a facile solvent-assisted exfoliation/blending approach using
dichlorobenzene and glycerol at a moderate temperature. The exfoliation of g-C3N4 followed by
wrapping on perovskite established an effective heterojunction between the materials for charge
separation. The conjugated 2D sheets of CN enabled better charge migration resulting in increased
photoelectrochemical performance. A blend composed of 40 wt% perovskites and CN performed
optimally, whilst achieving a photocurrent density as high as 1.5 mA cm−2 for sunlight-driven
water-splitting with a Faradaic efficiency as high as ∼88%.
This document summarizes research on the synthesis, properties, and applications of quantum dots. It discusses several common methods for synthesizing quantum dots, including colloidal synthesis, chemical vapor deposition, laser ablation, and molecular beam epitaxy. Colloidal synthesis is described for producing CdSe and InAs quantum dots through reaction of precursors in solution. Chemical vapor deposition and laser ablation techniques are also overviewed. The document then discusses some optical and electronic properties of quantum dots that enable applications in areas like electronics, biology, and energy.
This document discusses the performance of dye-sensitized solar cells that use different types of titanium dioxide photoelectrodes. Nanocrystalline and nanotube anatase TiO2 photoelectrodes were fabricated using a hydrothermal technique and their morphological characteristics were analyzed using scanning electron microscopy. The nanotube-based dye-sensitized solar cell was found to have a higher efficiency of 7.28% compared to the 6.6% efficiency of the nanocrystalline anatase-based cell, as measured by current density-voltage curves and incident photon to current conversion efficiency spectra. The nanotube structure allows for illumination from both the front and back sides.
The document presents a project on the synthesis of ZnSe nanocrystals. It discusses the objective to synthesize ZnSe nanocrystals and study their optical and electrical properties for application in photovoltaic cells. The methodology uses a solvothermal synthesis method with water as solvent to produce ZnSe nanocrystals. Characterization will include XRD, TEM, UV spectroscopy, SEM and FTIR to analyze the nanocrystals. Further work will dope the ZnSe with magnesium and send it for characterization at a university.
A NOVEL PRECURSOR IN PREPARATION AND CHARACTERIZATION OF NICKEL OXIDE (NIO) A...antjjournal
Synthesis of Nickel Oxide (NiO) nanoparticles and cobalt oxide (CO3O4) materials synthesis by aqueous chemical growth (ACG) Techniques. Oxide based material having a wide band gap, and suitable for optical devices,Optoelectronic devices, UV photodetector, and Light emitting diode LEDs. The analysis
and characterizationof Nickel Oxide (NiO) and cobalt oxide (CO3O4) nanoparticles by(1) X-ray diffraction (XRD), (2) Scanning electron microscopy (SEM), and (3) Ultraviolet–visible (UV–Vis) spectroscopy.
One pot synthesis of chain-like palladium nanocubes and their enhanced electr...tshankar20134
This document describes a one-pot synthesis of chain-like palladium nanocubes and their enhanced electrocatalytic activity. A simple aqueous approach is used to produce anisotropic cubic chain-like Pd nanostructures using the neurotransmitter 5-hydroxytryptamine. Scanning electron microscopy images show the nanocubes have sizes between 140-210 nm and form chain-like branched structures. Testing shows the cubic chain-like nanostructures have over 11 times greater electrocatalytic activity for oxidizing formic acid, methanol, and ethanol compared to spherical nanoparticles and commercial Pd/C catalysts. The enhanced performance makes them promising multipurpose catalysts for direct fuel cells.
Synthesis and Characterization of Cadmium Selenide NanoparticlesIRJET Journal
This document summarizes the synthesis and characterization of cadmium selenide (CdSe) nanoparticles. CdSe nanoparticles were synthesized using a co-precipitation method involving cadmium oxide, selenium dioxide, ammonia, and thioglycerol as a capping agent. The nanoparticles were characterized using optical microscopy and X-ray diffraction. XRD analysis confirmed the hexagonal wurtzite crystal structure of CdSe and showed peaks matching the standard pattern for CdSe. The synthesized CdSe nanoparticles have potential applications in solar cells, thin films, and biofluorescent tagging.
This document summarizes a study that synthesized nanoparticles of Y3+ substituted Ni1-x Cdx Yy Fe2-y O4 using a sol-gel autocombustion method. X-ray diffraction analysis revealed the nanoparticles had an average grain size between 12.5 to 34.8 nm and a spinel cubic structure. Ultraviolet visible spectroscopy and Fourier transform infrared spectroscopy were used to investigate the optical properties. The average band gap energy calculated using the Tauc method was 1.6294 eV, indicating the materials behaved as semiconductors. Increasing the Y3+ concentration slightly increased the lattice constant and slightly decreased the band gap energy.
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
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Monitoring and Managing Anomaly Detection on OpenShift.pdf
H41025565
1. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
RESEARCH ARTICLE
www.ijera.com
OPEN ACCESS
Effect of ZnS as an Impurity on the Physical Properties of KDP
Single Crystals
O. V. Mary Sheeja, C. K. Mahadevan
Physics Research Centre, S.T. Hindu College, Nagercoil-629002, India,
ABSTRACT
Pure and ZnS doped KDP (KH2PO4) single crystals were grown from aquous solutions by the slow evaporation
technique at room temperature. The influence of ZnS on the growth and characteristic properties of the KDP
single crystals were examined. Powder X-ray diffraction, atomic absorption spectroscopic and Fourier
transform infrared spectral measurements were done to characterize the grown crystals structurally and
chemically. Thermal and mechanical stabilities were understood by making respectively the thermogravimetric
and microhardness measurements. The optical transparency and second harmonic generation efficiency were
understood by making respectively the UV-Vis-NIR spectral and nonlinear optical measurements. The AC and
DC electrical measurements made on all the six grown crystals indicate a normal dielectric behaviour. The
electrical parameters, viz. dielectric constant, dielectric loss factor, AC electrical conductivity and DC electrical
conductivity are found to increase with the increase in temperature in the temperature range (40 – 150oC )
considered in the present study. The AC and DC activation energies estimated are found to vary nonlinearly
with the impurity concentration.
Keywords - Crystal growth, Doped crystals, KDP crystals, Physical Properties, X-ray diffraction
I.
INTRODUCTION
Single crystals of potassium dihydrogen
phosphate (KDP) draw the special attention due to
their unique collection of properties: the wide range
of transparency, electrooptical and piezooptical
effects, relatively high value of second-order
nonlinear susceptibility and the possibility of growing
the large-size crystals. The electrooptical property of
KDP leads to the application such as polarization
filter, electronic light shutter, optical rectifier,
electronic light modulator, piezo optic resonator,
transducer, etc. KDP belongs to scalenohedral (12
sided polyhedron) class of tetragonal crystal system
͞
having tetramolecular unit cell having I 42d space
group with lattice parameters: a=b=7.448 Å and
c=6.977 Å [1,2]. It is also ferroelectric, well below
room temperature, i.e below at its Curie temperature
Tc=123K [3,4]. Since KDP group crystal contain a
large number of hydrogen bond, they can effectively
capture impurity centers of a different nature. This
favours their use as model object in search of new
memory element, nonlinear optical and active laser
media [5,6]. Many researchers have tried to modify
the properties and growth rate of KDP crystal either
changing the growth conditions or by adding suitable
impurities [7-18]. The NLO and other properties of
the crystal have been improved by doping organic and
inorganic impurities [7-18].
A promising trend in the development of upto-date functional optical materials based on dielectric
is incorporation of nanoparticles into the crystalline
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matrices of traditional nonlinear optical materials, for
the improvement of the efficiency of their nonlinear
optical response. For instance, in [19] an attempt was
made to design a composite optical material
possessing the properties of active laser and nonlinear
optical media, the combination “KDP crystal-SiO2
particles” being used as a model system. The
influence of the size of the paricles on the probability
of their capture was studied, and the growing crystal
was shown to be able to capture effectively 1x10-2250µm SiO2 particles. Recently, the effect of titanium
dioxide nanoparticles on the functional properties of
KDP single crystals was studied [20-24]. It was
reported that the incorporation of titanium dioxide
nanoparticles into KDP matrix was shown to be the
composite system KDP:TiO2 having giant nonlinear
optical response. The influence of incorporated
Al2O3.nH2O nanoparticles on the growth kinetics of
KDP crystal faces and crystal perfection were also
investigated [25].
Nowadays nanocrystals are having an
increasing importance due to their influence in the
mechanical, electrical, optic and magnetic properties
due to the quantum confinement stimulated by size
decreasing. The incorporation of organic dye
molecules or nanoparticles subsystems in the crystal
lattice of the KDP type nonlinear optical (NLO)
material is the promising approach to the controlled
efficiency enhancement of their NLO response [20].
The synthesis and properties of highly luminescent IIVI compound semiconductor nanoparticles have been
55 | P a g e
2. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
extensively investigated from the basic research point
of view to the application field. With the
miniaturization of the particles the band gap expands
and the energy level of the core band shift towards
higher binding energy, and, subsequently, some
physical properties change. Electron and phonon
confinement is possible by II-VI compound
semiconductor when size of particles become less
than the Bohr radius of the bulk crystal exciton. This
leads to new physical properties and, consequently,
new applications arises in telecommunications and
transmission [26].
Recently, a strong interest has been devoted
to nanocrystals (NCs) of semiconductors embedded in
wide gap matrix such as glass [27-29]. Some reports
show the details of nanocrystals embedded in alkali
halides crystalline lattices. Researchers have
successfully embedded ZnO nanocrystals in KBr
crystal [30]. Boudine etal. [31-33] have analysed
alkali halides NaCl, KCl, KBr doped with II-VI
compound semiconductors CdTe, CdS. A study was
performed to prove the possibility of embedding II-VI
compound CdTe nanoparticle in KDP crystalline
matrix [34]. Such crystals are able to capture 2nm250µm particles. Balasubramanian et al [35] have
found that the density and mechanical properties of
TGS crystals were improved by doping water soluble
CdS nanoparticle dispersed in water.
Zns is an important semiconductor material
with large band gap (~3.6 eV) at room temperature
[36], high refractive index (2.35 at 632nm), high
effective dielectric constant (9 at1MHz) and wide
wavelength passband (0.4-13µm). Its optical
properties make it usful as a filter, reflector and
planar wave guide [37]. It has a vast potential for use
in optoelectronics and in electroluminescent devices
[38]. Generally II-VI compound including ZnS do not
dissolve in water. Now, the challenging question is
how to find the way to dissolve ZnS in the aqueous
solution of KDP used for the growth of single
crystals. So finding a simple synthetic method to
prepare ZnS is one of the main challenges of recent
research activities. The aggregation of nanocrystals
always decreases their nanoeffects. During the wet
chemical synthesis of nanoparticles, organic
stabilizers are usually used to prevent them from
aggregating by capping their surface. Moreover, the
introduction of stabilizers also influences on the
chemical properties as well as to the physical
properties of semiconductor materials, from stability
to solubility and to light emission. Therefore, proper
surface modification by stabilizer can remove the
localized surface trap states and significantly
increases the quantum yield of the excitonic emission.
However, only few reports describe the preparation of
water-soluble CdS nanoparticles with complex
molecules used as stabilizer and capping agent
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[39,40]. Recently Tang et al [41] reported that
ethylene diamine capped CdS nanoparticles enhances
the solubility of CdS nanoparticles in water.
In the present study, we have made an
attempt to introduce ZnS as dopant into the KDP
crystal matrix. We have prepared ZnS nanoparticles
by using ethylene diamine as a capping agent by a
simple solvothermal method using a domestic
microwave oven (Mahadevan‟s method [42-44]).
Pure and ZnS doped KDP single crystals (a total of
six) were grown and characterized chemically,
structurally, thermally, mechanically, optically and
electrically by using the available standard methods.
The results obtained are reported herein and
discussed.
II.
EXPERIMENTAL DETAILS
2.1 Preparation of ZnS nanoparticles
Mahadevan‟s method [42-44] was adopted to
obtain ethylene diamine capped ZnS nanoparticles
from zinc acetate dihydrate and thiourea (both AR
grade) dissolved in double distilled water in the
presence of ethylene diamine. The solubility was
found to be 0.71g/100ml of H2O. Details on the
preparation and characterization of ZnS nanoparticles
appear elsewhere.
2.2 Growth of single crystals
Pure and ZnS doped KDP single crystals
were grown by the free (slow) evaporation method
from saturated aqueous solutions of KDP. ZnS
nanoparticles (0.1g) were dissolved in double distilled
water (100ml) and used as the dopant. Five different
dopant concentrations were considered by adding
2,3,4,5 and 6 ml of the above solution to the KDP
solution. The above doped solutions were stirred well
and then allowed to equilibrate in a dust free zone at
room temperature. Small crystals appeared in the
beginning stage due to slow evaporation and then
grew larger in a considerable time. The grown
crystals are represented in the same order as Pure
KDP, ZKDP-1, ZKDP-2, ZKDP-3, ZKDP-4 and
ZKDP-5.
2.3 Characterization studies
Powder X-ray diffraction (PXRD) studies
were carried out on all the grown crystals using an
automated X-ray powder diffractometer (X-PERT
PRO PANalytical) with monochromated CuK α
radiation (λ=1.54056Å). The reflections were indexed
by following the procedures of Lipson and Steeple
[45]. Lattice parameters along with estimated
standard deviation (e.s.d.s) were also determined from
the indexed data. Fourier transform infrared (FTIR)
spectra were recorded for the Pure KDP and ZKDP-5
crystals by the KBr pellet technique using a Perkin
Elmer FTIR spectrometer in the wavenumber range
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3. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
400 - 4000 cm-1. Atomic absorption spectroscopic
(AAS) measurements were carried out for the doped
crystals using an AAS spectrometer (model AA6300). Thermogravimetric analysis (TGA) and
differential thermal analysis (DTA) were carried out
for the Pure KDP and ZKDP-5 crystals using a
thermal analyser (model SDT-Q600) in the nitrogen
atmosphere in the temperature range of room
temperature to 900o C at a heating rate of 10oC/min.
The UV-Vis-NIR spectra were recorded in the
wavelength range 190 - 1100nm using a Perkin Elmer
Lambda 35 spectrophotometer. The NLO property
was tested for all the six grown crystals by carrying
out the Kurtz and Perry [46] powder SHG test using a
Q-switched Nd:YAG laser (1064nm) (supplied by
Spectra Physics, USA). Microhardness measurements
were carried out on the (100) face of all the six grown
crystals
using
a
SHIMADZU
HMV-2T
microhardness tester with a diamond indentor.
Crystals with large surface defect-free (i.e.
without any pit or crack or scratch on the surface,
tested with a travelling microscope) size (>3mm)
were selected and used for the AC and DC electrical
measurements. The extended portions of the crystal
were removed completely and the opposite faces were
polished and coated with good quality graphite to
obtain a good conductive surface layer. The
dimensions of the crystal were measured using a
travelling microscope (Least count=0.001cm). The
DC electrical conductivity measurements were carried
out to an accuracy of ±2% for all the six grown
crystals along both a- and c- directions at various
temperatures ranging from 40-1500C by the
conventional two-probe method using a million
megohm meter in a way similar to that followed by
Mahadevan and his co-workers [47-49]. The DC
conductivity (σdc) of the crystal was calculated using
the relation:
σdc =dcrys/(RAcrys)
where R is the measured resistance, dcrys is the
thickness of the sample crystal and Acrys is the area of
the face of the crystal in contact with the electrode.
The capacitance (Ccrys) and dielectric loss factor
(tan𝛿) measurements were carried out for all the six
grown crystals to an accuracy of ±2% by the parallel
plate capacitor method using an LCR meter
(Systronics make) with a frequency of 1kHz at
various temperatures ranging from 40-1500C along
both a- and c- directions in a way similar to that
followed by Mahadevan and his co-workers [47-49].
In both the DC and AC electrical measurements, the
observations were made while cooling the sample
crystal and the temperature was controlled to an
accuracy of ±1%. The air capacitance (Cair) was also
measured but only at 400C since the temperature
variation of Cair was found to be negligible. As the
crystal surface area touching the electrode was
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smaller than the plate (electrode) area of the cell, the
dielectric constant of the crystal (εr) was calculated
using Mahadevans‟s formula [50,51]
where Ccrys is the capacitance with crystal (including
air), Cair is the capacitance of air and Aair is the area of
the electrode. The AC electrical conductivity (σac)
was calculated using the relation:
σac= ε0 εr ω tan𝛿,
where ε0 is the permittivity of free space and ω is the
angular frequency of the applied field.
III.
RESULTS AND DISCUSSION
3.1 Crystal growth, structurel analysis and
chemical composition
A photograph of the sample crystals grown
in the present study is shown in Figure 1. All the
grown crystals are stable in atmospheric air,
colourless and transparent. Figure 2(a) and 2(b)
shows the TGA and DTA curves for the Pure KDP
and ZKDP-5 crystals. This study reveals that Pure
KDP is thermally stable upto 212oC, after which the
sample undergoes an appreciable weight loss. But in
ZKDP-5 crystal, the decomposition temperature is
shifted to 211oC. There is a slight decrease of
temperature for doped crystals, suggesting that
substitution of ZnS slightly changes the thermal
stability of KDP crystal.
Fig-1: Photograph of the grown crystals
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4. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
Fig-2(a): TGA and DTA curves observed for the Pure
KDP crystal
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The indexed PXRD patterns observed in the
present study are shown in Figure 3. In the recorded
PXRD pattern, all peaks could be assigned to the
tetragonal structure and the appearance of strong and
sharp peaks in the PXRD pattern signify the good
crystalline and single phase nature of pure and ZnS
doped KDP crystals. The average lattice parameters
obtained from PXRD data along with the Zn atom
contents of doped crystals obtained through the AAS
measurements are provided in Table 1. The average
lattice parameters observed in the present study (see
Table 1) for the Pure KDP crystal agree well with that
reported in the literature [52]: This confirms the
identity of the substance. The observed increase of
lattice volume caused by the impurity addition
indicates that the impurity molecules have entered
into the KDP crystal matrix. The Zn atom contents
observed (see Table 1) endorse this result. So, the
present study indicates that it is possible that ZnS can
be doped to KDP crystal.
Table-1: Average lattice parameters and Zn atom
contents observed
Lattice parameters
Zn
content
(ppm)
a (Å)
c (Å)
Volume
(Å3)
Pure KDP
7.413(8)
6.942(9)
381.53
-
ZKDP-1
7.485(5)
7.026(5)
393.68
0.1135
ZKDP-2
7.429(3)
6.962(3)
384.27
0.1528
ZKDP-3
7.510(9)
7.044(6)
397.31
0.1144
ZKDP-4
7.468(6)
6.987(4)
389.64
0.1161
ZKDP-5
7.523(8)
7.063(4)
399.23
0.1659
Crystal
Fig-2(b): TGA and DTA curves observed for ZKDP-5
crystal
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5. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
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Fig-3: PXRD patterns of (a) Pure KDP, (b) ZKDP-1, (c) ZKDP-2, (d) ZKDP-3, (e) ZKDP-4 and (f) ZKDP-5
Figure 4 shows the FTIR spectra observed
for the Pure KDP and ZKDP-5. The vibrational band
assignments are provided in Table 2. Significant
difference could not be observed for the doped
crystals as the impurity concentrations considered are
small. The spectrum observed for the Pure KDP
compares well with that reported in the literature
which again confirms the material of the crystal. The
vibrational band assignments reported for Pure KDP
in the literature [53] are also given in Table 2 for
comparison.
Table-2: FTIR band assignments
Wavenumbers (cm-1) for
Pure
Pure KDP
KDP
ZKDP-5
(Present)
[55]
3941
3928
3917
3813
3793
3428
3423
-
-
-
3185
2782
-
2775
2464
2465
2486
2354
-
2276
-
1822
1642
1643
1607
1300
1095
904
542
458
1298
1097
906
544
452
1298
1101
894
550
462
240
220
200
180
Pure KDP
ZKDP-5
160
%T
140
120
100
80
60
40
20
0
500
1000
1500
2000
2500
3000
3500
4000
4500
-1
Wavenumber (cm )
Fig-4: FTIR spectra for the Pure KDP and ZKDP-5
crystals
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Assignment
O-H stretching
Free O-H stretching
Hydrogen bonded O-H
stretching
O-H stretching
P-O-H asymmetric
stretching
O=P-OH asymmetric
stretching
P-O-H bending
O=P-O stretching
O=P-OH symmetric
stretching
P=O stretching
P=O stretching
P-O-H stretching
HO-P-OH bending
PO4 stretching
59 | P a g e
6. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
where k1 is the material constant.
The plots of log P verses log d obtained are
shown in figure 6(b). The work hardening coefficient
or Meyer index (n) was determined from the slop of
these plots. The n values obtained are given in Table
3. According to Onitsch and Hanneman „n‟ should lie
between 1.0 and 1.6 for hard material and above 1.6
for soft ones [56]. The „n‟ values observed in the
present study are more than 1.6. This indicates that
all the six crystals grown belong to soft materials
category.
160
2
Hv(kg/mm )
3.2 Optical and mechanical properties
The optical transmission range and the
transparency cut off limits are important for NLO
materials, as it can be put into use only if it possesses
the required cut-off wavelength as well as low
absorption. The recorded UV-Vis-NIR spectra of
pure and ZnS doped KDP crystals are shown in
Figure 5. It was observed from the spectra that both
pure and ZnS doped KDP crystals have significantly
low cut-off wavelengths and good transmittances
towards the visible and infrared regions. The
percentages of optical transmission and cut-off
wavelengths observed for pure and ZnS doped KDP
crystals are provided in Table-3. The transparent
nature of these crystals observed in the visible region
is a desirable property for this material for NLO
applications.
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
120
80
60
30
T (%)
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30
400
800
2.1
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
1200
1.8
Fig-5: Transmission spectra of pure and ZnS doped
KDP single crystals
The SHG efficiency observed for pure and
ZnS doped KDP crystals are given in Table 3. It can
be observed that SHG efficiency increases due to
doping which indicates that all the six crystals grown
in the present study are NLO active.
The hardness of a material is a measure of
its resistance it offers to local deformations [54]. The
micro-indentation test is a useful method for studying
the nature of plastic flow and its influence on the
deformation of the materials. Higher hardness value
of a crystal indicates that greater stress is required to
create dislocation [55]. The plots of variation of
Vickers hardness number with applied load for pure
and ZnS doped KDP single crystals obtained in the
present study are shown in Figure 6(a). It can be seen
that the hardness value increases with the increase of
load for all the six crystals grown. The Hv value
increases upto a load of 100g, above which cracks
start developing which may be due to the release of
internal stress generation with indentation. The
Vicker hardness number (Hv) is defined as
Hv=1.8544 P/d2 kg/mm2
and the Meyer‟s law [52] is expressed as
P=k1dn
log P
Wavelength (nm)
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90
Fig-6(a): Plot of hardness number (Hv) Vs load (P)
0
0
60
Load P (g)
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
1.5
1.3
1.4
1.5
1.6
1.7
log d
Fig-6(b): Plot of log P Vs log d
Table-3: The cut off wavelengths, optical
transmission percentages, SHG efficiencies and work
hardening coefficients (n)
Optical
Cut-off
Work
transmiss wavelen SHG
hardening
Crystal
ion
gth
efficiency
coefficient,
(%)
(nm)
n
Pure
KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
58
330
1
2.64
45
67
48
65
53
29
450
250
342
337
1.863
1.794
1.181
1.969
1.731
2.74
2.64
3.86
3.96
2.67
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7. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
systematic variation is observed with the impurity
concentration (volume of ZnS solution added to the
KDP solution used for the growth of single crystals)
for all the above electrical parameters in the whole
temperature range considered in the present study.
This is illustrated in Figure 11-14.
3.3 Electrical properties
The dielectric parameters, viz. DC electrical
conductivity (σdc), dielectric constant (εr), dielectric
loss factor (tan𝛿) and AC conductivity (σac) values
obtained in the present study are shown in Figures 710. It can be seen that all the four parameters increase
with the increase in temperature. However, no
500
400
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
-7
DC conductivity (x10 mho/m)
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
-7
DC conductivity (x10 mho/m)
1000
0
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200
0
40
80
120
40
160
80
120
160
o
Temperature ( C)
o
Temperature ( C)
Along a- direction
Along c- direction
Fig-7: DC electrical conductivities (σdc) for pure and ZnS doped KDP crystals
28
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
16
Dielectric constant
Dielectric constant
24
8
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
21
14
0
40
80
120
40
160
80
120
160
O
Temperature ( C)
o
Temperature ( C)
Along a- direction
Along c- direction
Fig-8: Dielectric constants (εr) for pure and ZnS doped KDP crystals
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
3
Dielectric loss
Dielectric loss
3
2
1
2
1
0
0
40
80
120
o
Temperature ( C)
Along a- direction
160
40
80
120
160
o
Temperature ( C)
Along c- direction
Fig-9: Dielectric loss factors (tan𝛿) for pure and ZnS doped KDP crystals
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61 | P a g e
8. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
40
10
0
40
Pure KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
-7
AC conductivity (x10 mho/m)
-7
AC conductivity (x10 mho/m)
20
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80
120
20
0
160
40
80
o
120
160
o
Temperature ( C)
Temperature ( C)
Along a- direction
Along c- direction
Fig-10: AC electrical conductivities (σac) for the pure and ZnS doped KDP crystals
Moreover, the εr values (along c- directions) observed
for the ZnS doped crystal are less than that observed
for the pure KDP. The variation with ZnS
concentration is nonlinear. The decrease of εr value
due to ZnS addition indicates the improvement in
NLO property. This is in agreement with the SHG
efficiencies observed.
600
DC conductivity(x10 mho/m)
0
0
500
0
0
3
40 C
0
80 C
0
120 C
0
150 C
400
-7
40 C
0
80 C
0
120 C
0
150 C
-7
DC conductivity (x10 mho/m)
1000
200
0
6
0
ZnS solution (ml)
3
6
ZnS solution (ml)
Along a- direction
Along c- direction
Fig-11: Impurity concentration dependence of σdc observed for the pure and ZnS doped KDP crystals
24
0
40 C
0
80 C
0
120 C
0
150 C
28
16
Dielectric constant
Dielectric constant
0
40 C
0
80 C
0
120 C
0
150 C
8
0
3
ZnS solution (ml)
6
21
14
0
3
6
ZnS solution (ml)
Along a- direction
Along c- direction
Fig-12: Impurity concentration dependence of εr observed for the pure and ZnS doped KDP crystals
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9. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
www.ijera.com
3
0
40 C
0
80 C
0
120 C
0
150 C
3
2
2
Dielectric loss
Dielectric loss
0
40 C
0
80 C
0
120 C
0
150 C
1
1
0
0
0
3
0
6
3
6
ZnS solution (ml)
ZnS solution (ml)
Along a- direction
Along c- direction
Fig-13: Impurity concentration dependence of tan𝛿 observed for the pure and ZnS doped KDP crystals
600
AC conductivity(x10 mho/m)
0
10
0
0
0
40 C
0
80 C
0
120 C
0
150 C
400
-7
40 C
0
80 C
0
120 C
0
150 C
-7
AC conductivity (x10 mho/m)
20
3
6
ZnS solution (ml)
200
0
0
3
6
ZnS solution (ml)
Along a- direction
Along c- direction
Fig-14: Impurity concentration dependence of σac observed for the pure and ZnS doped KDP crystals
The experimental data and especially the
character of the temperature dependence of electrical
conductivity allowed the earlier workers to
understand that the electrical conductivity of KDP
crystals is determined by both the thermally
generated L-defects (vacant hydrogen bonds) and the
foreign impurities incorporated into the lattice and
generating L-defects there [57]. When performing
measurements, Lokshin [58] assumed that HPO42ions are also responsible for the formation of vacant
hydrogen bonds (L-defects). Therefore, the pH value
of the initial solution, which determines its ionic
composition, can be one of the most important factors
that affects crystal conductivity, because of the
HPO42- ion concentration in the solution at some pH
is higher by several orders of maginitude than the
concentration of any other impurity [59]. From the
above, it can be understood that the proton transport
depends on the generation of L-defects. Hence, the
increase of conductivity with the increase in
temperature observed for ZnS doped KDP crystals in
the present study can be understood as due to the
temperature dependence of the proton transport.
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Also, the conductivity increases smoothly through the
temperature range considered in the present study.
Plots between lnσdc and 103/T and between
lnσac and 103/T (not shown here) are found to be
nearly linear. So, the conductivity (DC and AC)
values were fitted correspondingly to the Arrhenius
relation:
σdc=σ0dcexp[-Edc/(kT)]
and σac=σ0acexp[-Eac/(kT)],
where σ0dc and σ0ac are the proportionality constants
(considered to be the characteristic constants of the
material), k is the Boltzmann constant and T is the
absolute temperature. The DC and AC activation
energies (Edc and Eac) were estimated using the slopes
of the corresponding line plots. The estimated DC
and AC activation energies for the pure and ZnS
doped KDP crystals grown in the present study are
given in Table 4. The Edc values are observed to be
more than the Eac values as expected. The low values
of Edc and Eac observed suggests that oxygen
vacancies may be responsible for conduction in the
temperature region considered in the present study.
63 | P a g e
10. O.V.Mary Sheeja et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 1( Version 2), January 2014, pp.55-65
Variation of dielectric constant with
temperature is generally attributed to the crystal
expansion, the electronic and ionic polarizations and
the presence of impurities and crystal defects. The
variation of εr at lower temperatures is mainly due to
the crystal expansion and electronic and ionic
polarizations. The increase of εr at higher
temperatures is mainly attributed to the thermally
generated charge carriers and impurity dipoles. It has
been shown by Varotsos [60] that the electronic
polarizability practically remains constant in the case
of ionic crystals. So, the increase in dielectric
constant with temperature is essentially due to the
temperature variation of ionic polarizability.
The ZnS is an ionic substance and is
expected to become Zn2+ and S2- ions in the solution.
In the KDP crystal matrix, some of these ions are
expected to occupy interstitial positions. This induces
bulk defect states due to competition in getting the
sites for the impurity ions to occupy. To some extent,
the impurity ions are expected to replace the ions in
KDP. So, it is expected to create a random
disturbance in the hydrogen bonding system in the
KDP crystal matrix. As the conduction in KDP
crystal is protonic, the random disturbance in the
hydrogen bonding system may cause the electrical
parameters to vary nonlinearly with the impurity
concentration.
Table-4: The activation energies (Eac and Edc)
estimated for pure and ZnS doped KDP crystals
Crystal
Pure
KDP
ZKDP-1
ZKDP-2
ZKDP-3
ZKDP-4
ZKDP-5
Activation energies (eV)
Along a- axis
Along c- axis
Eac (eV) Edc (eV) Eac
Edc (eV)
(eV)
0.148
0.275
0.209
0. 260
has been found to enhance the SHG efficiency and
tune the optical and electrical properties significantly.
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