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.
Spectroscopic studies on Mn2+ ions doped Cadmium Aluminum Fluoro Lead Borate ...IJERA Editor
This article reports on optical properties of Mn2+ (0.5 mol%): 49.5 B2O3 - 10PbO - 30CdO -10AlF3 glasses.
Optical absorption spectrum of the manganese ions doped glass exhibits broad absorption band at 473 nm.
Photoluminescence spectrum of Mn2+ (0.5 mol %): 49.5B2O3- 30CdO – 10PbO - 10AlF3 glass has revealed a red
emission at 618 nm with an excitation wavelength 467 nm.
Optimization of Coal Blending to Reduce Production Cost and Increase Energy E...inventionjournals
The productivity level of the electricity production is an important indicator in the power plant efficiency. A chase study in this research was choosen at coal power plant PT PJB UP Paiton which is the productivity level of the generated electricity decreases until below the production target level. It due to several factors such as quality of coal and plant design. Depletion of coal heating value (low rank coal) reduce total amount of enerated heat in boiler and finally increase unburned carbon, plant inefficiency, as well as the high production cost. On the other hand, utilizing the high rank coal cause more expensive price. Therefore, the optimiation of coal blending to obtain more plant efficiency and lower production cost is required. This research focus on optimization of low and high rank coal blending that can decrease the production cost and increase plat efficiency. The blending model was built by utilizing Finite Impulse Response Neural Network (FIR-NN) and variable selection is perform using Priciple Component Analys is (PCA) and Partial Least Square (PLS). The result of optimization resulted a decreasing the production cost up to 342 IDR/kWh.
Spectroscopic properties of lithium borate glass containing Sm3+ and Nd3+ ionsIJAAS Team
Lithium borate glass samples mixed with a different concentration of Sm3+ and Nd3+ ions organized by quenching technique. Structural, vibration groups and spectral properties of glass samples investigated using X-ray diffraction, FTIR, UV/Vis/NIR and photoluminescence spectroscopy. The X-ray confirmed the lithium borate glass samples containing Sm3+ and Nd3+ ions in the amorphous state. Luminescence spectra of glass samples excited at 400 nm recorded, here three luminescence bands observed in Visible region, which due to spectra materials (Sm3+, Nd3+). These indicate that these glass samples responsible orange emission and used in the improvement of materials for LED, and optical devices. The functional vibration groups of the glass matrix studied using FTIR spectroscopy.
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.
Infrared Spectral and EPR Studies of Mn2+ Ions Doped K2O - CdO - B2O3 - SiO2 ...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This paper reports on the preparation and optical characterization of Cu2+ (0.5 mol %): (49.5)B2O3 - 10PbO - 30CdO -10AlF3 (BPCA)glasses. Due to the homogeneous distribution of Cu2+ ions, the glasses are found to be in bright blue color has been noticed. From the XRD profile, amorphous nature the glass has been studied. Triogonal BO3 units transformed into tetrahedral BO4 units has evidenced from the FTIR spectrum of reference glass. From the measured absorption spectrum of the copper glass exhibits broad absorption band (2B1g→2B1g) at 760 nm have been measured. Emission spectrum of Cu2+ (0.5 mol %): B2O3- CdO – PbO - AlF3 glass has revealed a blue emission at 447 nm with an excitation wavelength 389 nm.
Spectroscopic studies on Mn2+ ions doped Cadmium Aluminum Fluoro Lead Borate ...IJERA Editor
This article reports on optical properties of Mn2+ (0.5 mol%): 49.5 B2O3 - 10PbO - 30CdO -10AlF3 glasses.
Optical absorption spectrum of the manganese ions doped glass exhibits broad absorption band at 473 nm.
Photoluminescence spectrum of Mn2+ (0.5 mol %): 49.5B2O3- 30CdO – 10PbO - 10AlF3 glass has revealed a red
emission at 618 nm with an excitation wavelength 467 nm.
Optimization of Coal Blending to Reduce Production Cost and Increase Energy E...inventionjournals
The productivity level of the electricity production is an important indicator in the power plant efficiency. A chase study in this research was choosen at coal power plant PT PJB UP Paiton which is the productivity level of the generated electricity decreases until below the production target level. It due to several factors such as quality of coal and plant design. Depletion of coal heating value (low rank coal) reduce total amount of enerated heat in boiler and finally increase unburned carbon, plant inefficiency, as well as the high production cost. On the other hand, utilizing the high rank coal cause more expensive price. Therefore, the optimiation of coal blending to obtain more plant efficiency and lower production cost is required. This research focus on optimization of low and high rank coal blending that can decrease the production cost and increase plat efficiency. The blending model was built by utilizing Finite Impulse Response Neural Network (FIR-NN) and variable selection is perform using Priciple Component Analys is (PCA) and Partial Least Square (PLS). The result of optimization resulted a decreasing the production cost up to 342 IDR/kWh.
Spectroscopic properties of lithium borate glass containing Sm3+ and Nd3+ ionsIJAAS Team
Lithium borate glass samples mixed with a different concentration of Sm3+ and Nd3+ ions organized by quenching technique. Structural, vibration groups and spectral properties of glass samples investigated using X-ray diffraction, FTIR, UV/Vis/NIR and photoluminescence spectroscopy. The X-ray confirmed the lithium borate glass samples containing Sm3+ and Nd3+ ions in the amorphous state. Luminescence spectra of glass samples excited at 400 nm recorded, here three luminescence bands observed in Visible region, which due to spectra materials (Sm3+, Nd3+). These indicate that these glass samples responsible orange emission and used in the improvement of materials for LED, and optical devices. The functional vibration groups of the glass matrix studied using FTIR spectroscopy.
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.
Infrared Spectral and EPR Studies of Mn2+ Ions Doped K2O - CdO - B2O3 - SiO2 ...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This paper reports on the preparation and optical characterization of Cu2+ (0.5 mol %): (49.5)B2O3 - 10PbO - 30CdO -10AlF3 (BPCA)glasses. Due to the homogeneous distribution of Cu2+ ions, the glasses are found to be in bright blue color has been noticed. From the XRD profile, amorphous nature the glass has been studied. Triogonal BO3 units transformed into tetrahedral BO4 units has evidenced from the FTIR spectrum of reference glass. From the measured absorption spectrum of the copper glass exhibits broad absorption band (2B1g→2B1g) at 760 nm have been measured. Emission spectrum of Cu2+ (0.5 mol %): B2O3- CdO – PbO - AlF3 glass has revealed a blue emission at 447 nm with an excitation wavelength 389 nm.
Preparation, Structure, and Characterization of Nd2mo2o9 fast Oxide Ion Condu...IJARIIT
The structure and ion conductivity of Nd2Mo2O9powders were synthesized by using Nd(NO2)3, MoO3, and aspartic acid (fuel) in assisted combustion method with heating at 550˚C for 6 hours. The thermal decomposition, phase identification, morphology, ionic conductivity of the samples were studied by TGA/DTA, XRD and SEM four probe D.C. method respectively. The formation of Nd2Mo2O9 was confirmed by FTIR studies. The synthesis and crystallization were followed by thermochemical techniques (TGA/DTA) studies. The synthesized materials showed reasonable ionic conductivity. These results indicate that assisted combustion method is a promising method to prepare nanocrystalline Nd2Mo2O9 for solid oxide fuel cell.
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.
This article reports on the optical analysis of Cu2+ (0.5 mol %): 59.5B2O3 – 20 TeO2 – 10CdO – 10Li2O glass.
From XRD spectrum , amorphous nature of the glass has been studied. Absorption spectrum of the copper glass
shows a broad absorption band (2B1g→2B1g) at 829 nm has been observed. Emission spectrum of Cu2+ (0.5 mol
%): 59.5B2O3 – 20 TeO2 – 10CdO – 10Li2O glass has exhibits a blue emission at 439 nm with an excitation
wavelength 379 nm.
Surfactant-assisted Hydrothermal Synthesis of Ceria-Zirconia Nanostructured M...IOSR Journals
CeO2–ZrO2 oxides were prepared by the surfactant-templated method using cetyl trimethyl ammonium bromide (CTAB) as template and modified with chromium nitrate. These were characterized by XRD, FT-IR, TEM, SEM, BET and TPD-CO2. The XRD data showed that as prepared CeO2-ZrO2 powder particles have single phase cubic fluorite structure. HRTEM shows mesoscopic ordering. Average particle size is 12-13 nm as calculated from particle histogram. The nitrogen adsorption/desorption isotherm were classified to be type IV isotherm, typical of mesoporous material. The presence of uni-modal mesopores are confirmed by the pore size distribution which shows pore distribution at around 60 A°. Catalytic activity was studied towards liquid-phase oxidation of benzene.
A facile method to prepare CdO-Mn3O4 nanocompositeIOSR Journals
CdO-Mn3O4 nanocomposite has been prepared by a simple solvothermal method using a domestic microwave oven. Cadmium acetate, manganese acetate and urea were used as the precursors and ethylene glycol as the solvent. The as-prepared sample was annealed for 1 hour in each case at different temperatures, viz. 100, 200 and 300°C. The as-prepared and annealed samples were characterized by X-ray diffraction and scanning electron microscopic analyses. Results indicate that annealing at 300°C is required to get the sample with high phase purity and homogeneity. The present study indicates that the method adopted can be considered as an economical and scalable one to prepare the proposed nanocomposite with reduced size, phase purity and homogeneity.
Synthesis, characterization and electrocatalytic activity of silver nanorods ...kutty79
This paper describes a simple method of synthesizing silver nanorods using the polyol process, where propylene glycol serves both as a reducing
agent and as a solvent in the presence of a capping reagent such as polyvinylpyrrolidone (PVP). The diameter and length of silver nanorods could be
controlled by changing the AgNO3/PVP ratio. The end-to-end assembly of the silver nanorods was found. The silver nanorods were characterized by
using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and absorption spectroscopy. The catalytic activity of a
glassy carbon electrode with Ag nanorods exhibits extraordinary electrocatalytic activities towards the electro-reduction of benzyl chloride.
Synthesis and Characterisation of Copper Oxide nanoparticlesIOSR Journals
Cupric oxide (CuO) nanoparticles were prepared by the chemical route by calcinations at a higher temperature from 300oC to 400 oC. For the comparison transmission electron microscopy (TEM) and x-ray diffraction (XRD) measurements were made through JCPDS. There is good agreement between data produced by spectroscopy and the microscopic measurements.
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.
Removal of lead ions by nife2 o4 nanoparticleseSAT Journals
Abstract Nickel ferrite nanoparticles have been prepared by polymeric precursor method. The nanoparticles application in the removal of lead ion was investigated. The results showed that the adsorptive properties were dependent on pH, duration and temperature. Highest percentage (99%) lead adsorption was observed under basic condition at room temperature during 1 h stirring. Analysis of lead adsorbed nickel ferrite by powder XRD, FTIR and XPS techniques revealed the adsorption took place based on hydroxide mechanism. The lead salt formed on the surface of the ferrite powder was identified to be lead carbonate and lead hydroxy carbonate at pH 7 and 9 respectively. Keywords: Nickel ferrite; Nanoparticles; Lead; Adsorption; Hydroxide
Electrochemical Synthesis of MoO3 Nanoparticles Effect of Temperature Convert...IJERA Editor
MoO3 nanorods were prepared by electrochemical reduction method using the tetra propyl ammonium bromide (TPAB) was structure directing agent in an organic medium viz. tetra hydro furan (THF) and acetonitrile (ACN) in 4:1 ratio and at current density 14mA &18 mA. The reduction process takes place under atmospheric condition over a period of 2 h. Dried sample was calcinated in muffle furnace at 500ºC. The parameters such as current density and concentration of stabilizers were used to control the size of nanorods. The synthesized MoO3 nanorods were characterized by using UV-Visible, FT-IR, XRD, SEM-EDS and TEM analysis techniques.
Report Mundo Hiperconectado Escenario 2020-2030Joan Sardà
Report con el desarrollo de la presentación Conexión Cliente. Cómo será en escenario en que competiremos en el futuro: global, urbano, conectado, instantáneo, basado en experiencias ... a velocidad exponencial.
Si te interesa integrarte en este grupo de reflexión o recibir información personalizada, puedes ponerte en contacto en www.conexioncliente.com
Preparation, Structure, and Characterization of Nd2mo2o9 fast Oxide Ion Condu...IJARIIT
The structure and ion conductivity of Nd2Mo2O9powders were synthesized by using Nd(NO2)3, MoO3, and aspartic acid (fuel) in assisted combustion method with heating at 550˚C for 6 hours. The thermal decomposition, phase identification, morphology, ionic conductivity of the samples were studied by TGA/DTA, XRD and SEM four probe D.C. method respectively. The formation of Nd2Mo2O9 was confirmed by FTIR studies. The synthesis and crystallization were followed by thermochemical techniques (TGA/DTA) studies. The synthesized materials showed reasonable ionic conductivity. These results indicate that assisted combustion method is a promising method to prepare nanocrystalline Nd2Mo2O9 for solid oxide fuel cell.
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.
This article reports on the optical analysis of Cu2+ (0.5 mol %): 59.5B2O3 – 20 TeO2 – 10CdO – 10Li2O glass.
From XRD spectrum , amorphous nature of the glass has been studied. Absorption spectrum of the copper glass
shows a broad absorption band (2B1g→2B1g) at 829 nm has been observed. Emission spectrum of Cu2+ (0.5 mol
%): 59.5B2O3 – 20 TeO2 – 10CdO – 10Li2O glass has exhibits a blue emission at 439 nm with an excitation
wavelength 379 nm.
Surfactant-assisted Hydrothermal Synthesis of Ceria-Zirconia Nanostructured M...IOSR Journals
CeO2–ZrO2 oxides were prepared by the surfactant-templated method using cetyl trimethyl ammonium bromide (CTAB) as template and modified with chromium nitrate. These were characterized by XRD, FT-IR, TEM, SEM, BET and TPD-CO2. The XRD data showed that as prepared CeO2-ZrO2 powder particles have single phase cubic fluorite structure. HRTEM shows mesoscopic ordering. Average particle size is 12-13 nm as calculated from particle histogram. The nitrogen adsorption/desorption isotherm were classified to be type IV isotherm, typical of mesoporous material. The presence of uni-modal mesopores are confirmed by the pore size distribution which shows pore distribution at around 60 A°. Catalytic activity was studied towards liquid-phase oxidation of benzene.
A facile method to prepare CdO-Mn3O4 nanocompositeIOSR Journals
CdO-Mn3O4 nanocomposite has been prepared by a simple solvothermal method using a domestic microwave oven. Cadmium acetate, manganese acetate and urea were used as the precursors and ethylene glycol as the solvent. The as-prepared sample was annealed for 1 hour in each case at different temperatures, viz. 100, 200 and 300°C. The as-prepared and annealed samples were characterized by X-ray diffraction and scanning electron microscopic analyses. Results indicate that annealing at 300°C is required to get the sample with high phase purity and homogeneity. The present study indicates that the method adopted can be considered as an economical and scalable one to prepare the proposed nanocomposite with reduced size, phase purity and homogeneity.
Synthesis, characterization and electrocatalytic activity of silver nanorods ...kutty79
This paper describes a simple method of synthesizing silver nanorods using the polyol process, where propylene glycol serves both as a reducing
agent and as a solvent in the presence of a capping reagent such as polyvinylpyrrolidone (PVP). The diameter and length of silver nanorods could be
controlled by changing the AgNO3/PVP ratio. The end-to-end assembly of the silver nanorods was found. The silver nanorods were characterized by
using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and absorption spectroscopy. The catalytic activity of a
glassy carbon electrode with Ag nanorods exhibits extraordinary electrocatalytic activities towards the electro-reduction of benzyl chloride.
Synthesis and Characterisation of Copper Oxide nanoparticlesIOSR Journals
Cupric oxide (CuO) nanoparticles were prepared by the chemical route by calcinations at a higher temperature from 300oC to 400 oC. For the comparison transmission electron microscopy (TEM) and x-ray diffraction (XRD) measurements were made through JCPDS. There is good agreement between data produced by spectroscopy and the microscopic measurements.
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.
Removal of lead ions by nife2 o4 nanoparticleseSAT Journals
Abstract Nickel ferrite nanoparticles have been prepared by polymeric precursor method. The nanoparticles application in the removal of lead ion was investigated. The results showed that the adsorptive properties were dependent on pH, duration and temperature. Highest percentage (99%) lead adsorption was observed under basic condition at room temperature during 1 h stirring. Analysis of lead adsorbed nickel ferrite by powder XRD, FTIR and XPS techniques revealed the adsorption took place based on hydroxide mechanism. The lead salt formed on the surface of the ferrite powder was identified to be lead carbonate and lead hydroxy carbonate at pH 7 and 9 respectively. Keywords: Nickel ferrite; Nanoparticles; Lead; Adsorption; Hydroxide
Electrochemical Synthesis of MoO3 Nanoparticles Effect of Temperature Convert...IJERA Editor
MoO3 nanorods were prepared by electrochemical reduction method using the tetra propyl ammonium bromide (TPAB) was structure directing agent in an organic medium viz. tetra hydro furan (THF) and acetonitrile (ACN) in 4:1 ratio and at current density 14mA &18 mA. The reduction process takes place under atmospheric condition over a period of 2 h. Dried sample was calcinated in muffle furnace at 500ºC. The parameters such as current density and concentration of stabilizers were used to control the size of nanorods. The synthesized MoO3 nanorods were characterized by using UV-Visible, FT-IR, XRD, SEM-EDS and TEM analysis techniques.
Report Mundo Hiperconectado Escenario 2020-2030Joan Sardà
Report con el desarrollo de la presentación Conexión Cliente. Cómo será en escenario en que competiremos en el futuro: global, urbano, conectado, instantáneo, basado en experiencias ... a velocidad exponencial.
Si te interesa integrarte en este grupo de reflexión o recibir información personalizada, puedes ponerte en contacto en www.conexioncliente.com
Tutorial breve para el uso del foro en melodysoftluisrosales
Tutorial breve para comprender las funciones básicas del Foro Virtual, en la plataforma Melodysoft. Elaborado con fines didácticos por el Prof. Luis Rosales Delgado, Mayo 2011. @lrosalesdelgado
The Six Highest Performing B2B Blog Post FormatsBarry Feldman
If your B2B blogging goals include earning social media shares and backlinks to boost your search rankings, this infographic lists the size best approaches.
Each technological age has been marked by a shift in how the industrial platform enables companies to rethink their business processes and create wealth. In the talk I argue that we are limiting our view of what this next industrial/digital age can offer because of how we read, measure and through that perceive the world (how we cherry pick data). Companies are locked in metrics and quantitative measures, data that can fit into a spreadsheet. And by that they see the digital transformation merely as an efficiency tool to the fossil fuel age. But we need to stretch further…
Spectral studies of praseodymium doped heavy metal borate glass systemsinventy
Praseodymium doped HMO glasses are fabricated with the following compositions using conventional melt quenching technique. The compositions of the glass systems are 12 ZnO + 33 B2O3 + (50-x) PbO + (x+10) CaO + 4 Al2O3 + 1 Pr6O11 where (x = 0,10,20,30 and 40 mol %.). Certain physical properties of these systems have been evaluated and reported. Spectral data for all these systems were recorded for X-ray diffraction, Optical absorption and Fluorescence properties. The Judd-Ofelt intensity parameters Ωλ ( λ = 2,4,6) were evaluated from the spectral data and in turn employed to evaluate the lasing parameters of Pr3+ HMO glass systems such as radiative transition probabilities (A), radiative life-times (τR), branching ratios (βR) absorption cross-sections (σa) and Stimulated emission cross-sections (σe). The experimental and calculated branching ratios (βR) for the lasing transitions 3P0 3H4, 3P0 3H6, and 3P0 3F2 are found to be in good agreement in the present work.
Spectroscopic and Physical Properties of Mn2+ spin probe in RO-P2O5-ZnO-Pb3O4...IJERA Editor
RO-P2O5-ZnO-Pb3O4 (R=Li, Na and K) glasses containing 0.1concentrations of MnO have been prepared. The structural, optical and physical properties of prepared glasses are studied by XRD, UV-Visible, EPR and FTIR techniques. The nature of local symmetry and structural information of the neighboring atoms of dopant ions (Mn2+) in the host matrix have been understood by evaluating the crystal field strength (Dq) and Racah (B & C) parameters. The combined analysis of optical absorption and EPR spectroscopy has indicated that the manganese ions exist in Mn2+ (in octahedral) local coordination sites. FTIR results showed that PO4 are the main structural unit of the glass system and the manganese ions are located in the glass matrix network.
Application of Fe3O4 Sphere Doped with Zn for Enhanced Sonocatalytic Removal ...ijtsrd
Fe3O4 sphere doped Zn were successfully prepared by the simple one pot solvothermal method. Morphology and structure of the as synthesised products was checked through the XRD, SEM, HRTEM techniques. The Fe3¬O4 hollowsphere doped showed the high photocatalytic activity for degradation of hexavalent chromium under visible light irradiation. The effects of reaction conditions such as initial pH, photocatalyst dosage and hexavalent chromium contratentation were also studied systematically. The stability of the catalsyts and and possible catalytic mechanism was also proposed. The results indicate that Fe3O4 sphere doped Zn can be promising catalyst for photo reduction of hexavalent chromium. Xuan Sang Nguyen "Application of Fe3O4 Sphere Doped with Zn for Enhanced Sonocatalytic Removal of Cr (VI) From Aqueous Solutions" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-1 , December 2021, URL: https://www.ijtsrd.com/papers/ijtsrd47862.pdf Paper URL: https://www.ijtsrd.com/medicine/other/47862/application-of-fe3o4-sphere-doped-with-zn-for-enhanced-sonocatalytic-removal-of-cr-vi-from-aqueous-solutions/xuan-sang-nguyen
CHEMICAL DURABILITY AND CHARACTERIZATION OF THE PHOSPHATE GLASSES CONTAINING ...ijac123
In order to prepare a high quality glass with high water resistance, we investigated chromium iron phosphate glass because of its improved chemical durability. The introduction of chromium in sodiumiron-phosphate glasses is used to compare its effect with iron in inhibition of corrosion. The sodiumchromium-iron phosphate glass of composition 30Fe2O3-xCr2O3-(15-x)Na2O-55P2O5 (mol %),with (0≤x≤4) was produced by melting batches of (99,98% pure) Cr2O3, Fe2O3, Na2CO3, and (NH4)2HPO4 at 1080°C for one hour and pouring the liquid into the bench. The sample was annealed at 650°C for 48h. We have performed the measurement of X-Ray diffraction, and Infra Red spectroscopy. The chemical durability was evaluated by weight losses of glass samples after immersion in hot distilled water (90°C) for 30 days. Weight loss measurements showed a good chemical durability unlike borosilicate glass.
A Simple Thermal Treatment Synthesis and Characterization of Ni-Zn Ferrite (N...IOSR Journals
Cubic structured nickel-zinc ferrite nanoparticles (Ni0.5Zn0.5Fe2O4) have been synthesized by thermal treatment method. This simple procedure employed an aqueous solution containing only metal nitrates as precursors, polyvinyl pyrrolidone as a capping agent, and deionized water as a solvent. The solution was thoroughly stirred for 2 hour, dried at 353 K for 3 hour, the dried material crushed into powder and calcined the powder at 873 K to remove organic substances and crystallize the particles. The microstructure properties of the prepared ferrite nanoparticles were measured using FTIR, XRD, TEM, and EDX and the magnetic properties were determined using VSM and EPR. The average particle size increased from 7 to 22 nm with the increase of calcination temperature from 723 to 873 K. The saturation magnetization, coercivity field, and g-factor increased respectively from 24 emu/g, 11 G, and 2.0673at 723 K to 38 emu/g, 60 G, and 2.1227 at 873 K. This method offers simplicity, a low cost, and an environmentally friendly operation since it produces no by-product effluents.
Growth and Characterization of Barium doped Potassium Hydrogen Phthalate Sing...IJERA Editor
The Non Linear Optical materials have acquired new significance with the advent of a large number of devices
utilizing solid state Laser sources. Potassium Hydrogen Phthalate one of the Non Linear Optical material having
superior non linear optical properties has been exploited for variety of application. In the present work, KHP
single crystals were grown by slow evaporation technique with Barium metal ion as a dopant. The grown
crystals were subjected to powder XRD analysis and the result shows that the Ba2+ ions does not alter the crystal
structure, but it enter into the crystal lattice of pure KHP. The optical transparency of the grown crystal was
studied by UV-Visible spectroscopy, the molecular structure was confirmed by FTIR analysis and its thermal
stability by TG/DTA analysis. The improved SHG efficiency of barium doped Potassium Hydrogen Phthalate
crystal could enhance the nonlinearity behaviour. In addition to this, the electrical parameter such as dielectric
constant was studied in detail.
Thermal Oxidation of Copper for Favorable Formation of Cupric Oxide (CuO) Sem...IOSR Journals
Thermal oxidation of copper has been restudied to control the formation of photovoltaic active cupric oxide (CuO) phase against the cuprous oxide (Cu2O) phase. It has been established that the thermal oxidation of copper is governed by the outward lattice diffusion and grain boundary diffusion of copper ions at the interface. The lattice diffusion favors the formation of Cu2O phase whereas grain boundary diffusion favors the formation of CuO phase. In the present work, a fine copper powder is taken as starting material for thermal oxidation to increase the grain boundary diffusion and to study its on phase formation. Further, to suppress the grain boundary diffusion the starting material is chemically passivated with diethylenetriamine and olelamine to chameically passivated the surface defects. Thermal oxidation of these pre-treated materials is carried out in open air at temperature 500 oC and 700 oC to study the phase formation. The resulting materials are characterized by x-ray diffraction and scanning electron microscopy. These studies clearly confirm that grain boundary diffusion or defect mediated diffusion due to small particle size and more surface atoms of copper favor the formation of CuO at low temperature in case of pure copper, whereas the chemical passivation and high temperature heating favours the formation of Cu2O phase and hence the resulting material is biphasic. Hence, the present study is useful information in controlling the phase formation of copper oxide to obtain more photoactive material that is CuO.
Influence of concentration on the structural, optical and electrical properti...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
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Y04505127134
1. C. Parthasaradhi Reddy et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 5), May 2014, pp.127-134
www.ijera.com 127 | P a g e
Optical and Dielectric Properties of Cr3+
& Cu2+
:P2O5-ZnO-LiF
Glasses
C. Parthasaradhi Reddy*
, V. Naresh, R. Ramaraghavulu, B.H. Rudramadevi and
S. Buddhudu
Department of Physics, Sri Venkateswara University, Tirupati 517 502, India.
ABSTRACT
The present paper reports on the results concerning structural, thermal, optical (absorption & emission),
dielectric and ac conductivity properties of host glass in the chemical composition of 50P2O5-30ZnO-20LiF
(PZL), and two different transition metal ions doped glasses such as (0.5 mol%) Cr3+
:49.5P2O5-30ZnO-20LiF
and (0.5 mol%) Cu2+
:49.5P2O5-30ZnO-20LiF glasses have successfully been prepared by a melt quenching
technique. Thermal analysis has been carried out on the host (PZL) precursor chemical mix in evaluating weight
loss from its TG profile and glass transition temperature (Tg) and crystalline temperature (Tc) from its DTA
profile. The presence of Cr3+
and Cu2+
has been confirmed from their EDX profiles and absorption spectra.
From the absorption spectrum of Cr3+
: PZL glass, a couple of bands at 460 nm (4
A2g (F) 4
T1g (F)) and 664 nm
(4
A2g (F) 4
T2g (F)) have been displayed where as a broad absorption band at 824 nm (2
B1g → 2
B2g) is
observed from Cu2+
: PZL optical glass. The nature of local symmetry and structural information of the
neighboring atoms of dopant ions (Cr3+
& Cu2+
) in the host matrix have been understood by evaluating the
crystal field strength (Dq) and Racah (B & C) parameters. The emission spectrum of Cr3+
: PZL glass exhibits
emissions at 442 nm, 490 nm, 590 nm and 650 nm with an excitation at λexci = 368 nm. While in case of Cu2+
:
PZL glass, three emission bands are located at 436 nm, 542 nm and 652 nm with an excitation at λexci = 312 nm
have been observed. The frequency dependence of ac conductivity (a.c) and dielectric parameters (' and tan)
in the frequency range 1 Hz to 1MHz at room temperature for these glasses has been studied. The low frequency
dispersion in the profiles of dielectric constant and loss tangent would be resulting in because of space charge
polarization effect at the electrode-electrolyte interface and it is also noticed that a.c increases in accordance
with frequency change.
Keywords: Optical glasses and Dielectric properties.
I. INTRODUCTION
The oxide glasses containing transition
metal (TM) ions are of great interest, because these
ions exists in multivalent oxidation states in glassy
matrix exhibiting interesting behaviors like optical,
semiconducting and magnetic properties [1-3].
Among different types of glasses, the phosphate
glasses are considered to be significant in nature
because of their possessing unique performance
displaying high transparency, good thermal
expansion coefficient, lower refractive index, with an
extended transmission ability from near UV to
middle IR demonstrating their suitability as
luminescent potential optical materials [4-11]. In
Such glasses, chemical durability has been found to
be enhanced with an addition of modifier salts like
LiF, ZnO, etc. LiF increases the UV extension ability
and ZnO improvises the thermal stability with
ensured chemical durability. Optical, electronic and
magnetic properties of these glasses depend on the
relative proportion of different valence states of the
transition metal/ rare earth ions. In the present work,
we have taken up a glass in a general composition of
50P2O5-30ZnO-20LiF to incorporate with Cr2O3 and
CuO ions based on their usefulness as optical
materials [12, 13].
Bright and prominent bluish green colour
could be found due to the presence of Cu2+
ions from
the point of view of ligand field theory. The
electronic structure of the copper atom is [Ar] 3d10
4s1
; and its stable ionic states are Cu+
and Cu2+
; the
cuprous (Cu+
) ion, having its five d- orbitals
occupied, thus prevents display of colouring, while
Cu2+
ions create colour centres with absorption bands
in NIR wavelength region; although Cu2+
ion doped
materials would be in blue and sometimes in green
colour in its visual appearance [14, 15]. The
chromium ion, Cr3+
(d3
), gives rise to the free ion
terms of 4
F, 4
P, 2
G and several other doublet states, of
which 4
F is the ground state. In an octahedrally
coordinated system in the weak fields, 4
F splits as
4
A2g(F), 4
T2g(F) and 4
T1g(F) whereas 4
P transforms as
4
T1g(P). In the doublet states, 2
G splits as 2
A1g(G),
2
Eg(G), 2
T1g(G) and 2
T2g(G). The weak field terms
4
A2g(F), 2
Eg(G), 2
T1g(G) and 2
T2g(G) correspond to
the lowest strong field configuration (t2g)3
.The states
RESEARCH ARTICLE OPEN ACCESS
2. C. Parthasaradhi Reddy et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 5), May 2014, pp.127-134
www.ijera.com 128 | P a g e
4
T1g(F) and 4
T2g(F) correspond to (t2g) 2
(eg) 1
and
4
T1g(P) corresponds to (t2g)1
(eg) 2
. The ground state is
4
A2g(F) at all strengths of the crystal field. Thus, only
three spin allowed transitions arise from 4
A2g(F) to
4
T2g(F), 4
T1g(F) and 4
T1g(P) states in addition to
several spin forbidden transitions [16, 17]. Latter on
dielectric and conductivities studies were carried for
the host, chromium and copper ion containing glasses
at room temperature in the frequency range of 1Hz -
1MHz.
II. EXPERIMENTAL STUDIES
By employing melt quenching method, host
glass with and without transition metal ions as
dopants in the following chemical composition were
prepared:
(i) 50 P2O5 - 30 ZnO - 20 LiF (host glass)
(ii) 0.5 mol % (Cr2O3): 49.5P2O5-30ZnO-20LiF
(iii) 0.5 mol % (CuO): 49.5P2O5-30ZnO-20LiF
NH4H2PO4, ZnCO3, LiF, Cr2O3 and CuO of
analytical grade were used as starting chemicals. All
the chemicals were weighed in 10 g batch each
separately, thoroughly mixed using an agate mortar
and a pestle and then each of those was transferred
into porcelain crucible and heated in an electric
furnace for melting them for an hour at 950 °C. These
melts were stirred occasionally in obtaining a
homogeneous and to reduce bubble formation. Such
melts were later on poured in rectangular blocks and
quenched to obtain glasses in rectangular designs and
a thickness of 0.5 cm and these glasses were further
characterized. For an easy reference the prepared
glasses were labled as host PZL, Cu2+
: PZL, Cr3+
:
PZL.
XRD profiles were recorded for the glass
samples on a Seifert X-ray Diffractometer (model
3003TT) with Cu Kα radiation (λ = 1.5406 Å) at 40
KV and 20 mA with a Si detector and 2θ = 10o
and
60o
at the rate of two degrees per minute.
Simultaneous measurement of TGA and DTA was
carried out on a NetZsch STA 409 at a heating rate of
10 o
C/min with N2 as the purging gas. The elemental
analysis for the prepared glasses was done using
EDAX technique. Absorption spectra of glasses were
measured on a Varian-Cary-Win Spectrometer
(JASCO V-570). The emission spectrum of 0.5 mol%
CuO and 0.5 mol% Cr2O3 doped glasses were
measured in a steady state mode on a SPEX Flurolog-
3 (Model-II) Fluorimeter. Dielectric and conductivity
measurements were carried using a two electrode cell
configuration at room temperature over a frequency
range of 1 Hz – 1 MHz at ac voltage strength of 0.5
Vrms on a Phase Sensitive Multimeter (PSM 1700) in
LCR mode.
III. RESULTS AND DISCUSSION
Fig. 1 shows the XRD profile of the host
PLZ glass, exhibiting a broad diffusion peak between
2 values of 20°-30°, confirming amorphous nature
of the prepared glasses. Similar nature has been
observed in the case of transition metal ions doped
PZL glasses.
Fig.1: XRD profile of host P2O5-ZnO-LiF (PZL)
glass.
From Fig.2, TG profile reveals that the
weight loss takes place in a multi step process in the
measured range from 30 °C – 700 °C. The total
weight loss in the sample has been found to be 55 %
due to decomposition of H2O and CO2 and above 460
°C no major weight loss has been noticed due to the
formation of pure compound.
Fig.2: TG-DTA profiles of P2O5-ZnO-LiF (PZL)
glass precursor chemicals mix.
The DTA profile of host precursor
chemicals mix shows an endothermic peak at 162 o
C
which is attributed to the partial melting of small
percentage of impurities and due to phase changes in
P2O5. The glass transition temperature (Tg) and
crystalline temperature (Tc) are noticed at 375 °C and
500 °C.
3. C. Parthasaradhi Reddy et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 5), May 2014, pp.127-134
www.ijera.com 129 | P a g e
The presence of transition metals (CuO &
Cr2O3) in the chemical composition of the host glass
are verified separately from their EDAX analysis as
shown in Figs.3 (a, b & c).
Fig.3: EDAX profile of (a) host PZL, (b) Cr3+
: PZL
and (c) Cu2+
: PZL glasses.
In Fig.4 (a, b & c), optical absorption of the
host (PZL) and the Cr2O3: PZL and CuO: PZL
glasses are shown. The absorption edge for the host
glass lies in the UV region. From the absorption
spectrum of Chromium ion containing glass, a couple
of bands at 460 nm and 664 nm assigned to the spin
allowed optical d-d transitions of 4
A2g (F) 4
T1g (F)
and 4
A2g (F) 4
T2g (F) respectively, which are
characteristic bands of Cr3+
ions in octahedral
symmetry [18, 19]. With regard to absorption
spectrum of the glass containing Copper ion, it has
been noticed that a broad band arises in Vis-NIR
region around 824 nm assigned to the characteristic
electronic transition of 2
B1g→2
B2g. This confirms that
copper ions in the glass matrix exhibit Cu2+
oxidation
state due to their octahedral coordination [20, 21].
Fig.4: Optical absorption spectra of (a) host PZL,
(b) Cr3+
: PZL and (c) Cu2+
: PZL glasses.
3(a)
3(b)
3(c)
4(a)
4(b)
4(c)
4. C. Parthasaradhi Reddy et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 5), May 2014, pp.127-134
www.ijera.com 130 | P a g e
In order to have a better understanding of
the nature of local symmetry, distortions and
structural information on the neighboring atoms of
dopant ions (Cr3+
& Cu2+
) from the absorption
spectrum, crystal field strength Dq and Racah
parameters B & C (electron–electron interaction
parameters) are obtained [22, 23]. From Fig. 4(b) the
crystal field strength parameter (Dq) gives the energy
difference between ground state and first excited state
of Cr3+
, 4
A2g and 4
T2g respectively, and the equation
is of the form:
4 4
2 210 ( )g gDq E A T ... (1)
E is the energy difference between two peaks of
Cr3+
, at 4
T1g and 4
T2g respectively, and the equation is
given by:
4 4
1 2( ) ( )g gE E T E T ... (2)
The Racah parameter B (electrostatic
parameter which is a measure of the inter-electronic
repulsion) is calculated from the following formula:
2
10
15 8
E E
Dq DqB
Dq E
Dq
... (3)
The energy of the 4
T2g depends on the Dq
and B, the Dq value calculated for 4
A2g 4
T2g
transition from eq. (1) is 1506.02 cm-1
and the energy
difference E from eq (2) is found to be at 6678.9
cm-1
. Substituting the obtained values of Dq and E
in the eq (3), B is evaluated to be 693 cm-1
. The value
of C is evaluated from the equation given below:
22 1.8( ) 7.9
3.05
BE E B
Dq
C
... (4)
here E(2
E) = 14044.9 cm-1
taken from the earlier
reports [23], using the values of Dq, E and B, C is
evaluated to be 4691.8 cm-1
. The value of Dq/B <<
2.3, then Cr3+
ions lies in weak crystal field sites or
else if Dq/B >> 2.3, then Cr3+
ions lies in strong
crystal field sites and for intermediate crystal fields
Dq/B ≈ 2.3. For the present glass system the value of
Dq/B (4.43) >> 2.3, implies that Cr3+
ions lies in
strong crystal field sites. From Fig. 4(c), crystal field
strength (Dq) 2
B1g→2
B2g is calculated from:
2 2
1 210 ( )g gDq E B B ... (5)
It is found to be 1213.5 cm-1
. E and B, C
could not be calculated, as the absorption spectrum of
CuO: PZL glass could exhibit only a broad band
covering Vis-NIR region.
Figs. 5 (a & b) show the excitation and
emission spectra of 0.5 mol% Cr2O3: 49.5P2O5-
30ZnO-20LiF glass. The excitation spectrum exhibits
a band at 368 nm, which has been used in the
measurement of emission spectrum of Cr3+
glass.
From the emission spectrum of Cr3+
: PZL glass, four
emission bands at 442 nm (blue region), 490 nm
(yellow), 590 nm (orange) and 650 nm (red)
respectively have been observed[24].
Fig.5: (a) Excitation and (b) emission spectra of
Cr3+
: PZL glasses.
The excitation and emission spectra of 0.5
mol% CuO: 49.5P2O5-30ZnO-20LiF glass are
presented in Figs. 6 (a & b). The emission spectrum
with an excitation at 312 nm is shown in Fig. 6(b),
reveals three emissions at 436 nm (blue), 542 nm
(green), and 652 nm (red) respectively of Cu2+
ion
glass [25, 26].
5(a)
5(b)
5. C. Parthasaradhi Reddy et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 5), May 2014, pp.127-134
www.ijera.com 131 | P a g e
Fig.6: (a) Excitation and (b) emission spectra of
Cu2+
: PZL glasses.
Dielectric properties arise due to ionic
diffusions with in a conducting material when electric
field is applied. The charge carriers in the glass
cannot move freely through a glass matrix but they
can be displaced and polarized as response to an
applied alternating field. In the dielectric studies, the
complex permittivity of the system is calculated
using the impedance data [27]:
1
' ''j
j C
... (6)
where Z*
is the complex impedance, Co is the
capacitance of free medium. The real part of
permittivity (dielectric constant) represents the
polarizability of the material, while the imaginary
part (dielectric loss) " represents the energy loss due
to polarization and ionic conduction. The dielectric
parameters (dielectric constant (), dielectric loss
tangent (tan )) and ac ac conductivities are
calculated using the formulae [27]:
'
Cd
... (7)
''tan
'
... (8)
''ac
... (9)
where C is the capacitance of the glass sample, o is
the permittivity of the free space (8.85x 10-12
Fm)
and A is the cross-sectional area of electrode.
The variation of dielectric constant (') at
room temperature in the frequency range 1Hz-1MHz
for host (PZL), Cu2+
: PZL and Cr3+
: PZL glasses are
shown in Fig.7(a). All the three profiles have
exhibited same trend of rapid decrease in dielectric
constant with an increase in the frequency and finally
reaching to a constant value.
Fig.7 (a): Variation of dielectric constant (') as a
function of log (f) at room temperature for host PZL,
Cu2+
: PZL and Cr3+
: PZL glasses.
At low frequencies, dielectric constant
profile exhibits a high dispersion, because the ions
are not in a position to diffuse themselves along with
the electric field direction and as a result, charges
accumulate in space charge region at the electrode-
electrolyte interface due to net polarization effect. At
higher frequencies, the periodic reversal of electric
field at interface occurs so fast that no excess ions
accumulate in the electric field direction [28] and
hence, the dielectric constant is lowered by
weakening of ion-ion interaction in the dipoles and as
a result their contribution to the polarization would
be reduced.
The dielectric loss tangent (tan) is the
phase difference due to the loss of energy within the
sample. The contribution to the dielectric loss is
mainly attributed to thermally activated relaxation of
freely rotating dipoles trying to align themselves in
the applied field direction.
Cu2+
:PZL glass
Cu2+
:PZL glass
emi = 436 nm
exci = 312 nm
6(a)
6(b)
6. C. Parthasaradhi Reddy et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 5), May 2014, pp.127-134
www.ijera.com 132 | P a g e
Fig.7 (b): Variation of dielectric loss (tan) as a
function of log (f) at room temperature for host PZL,
Cu2+
: PZL and Cr3+
: PZL glasses.
In Fig.7(b), the dependence of dielectric loss
tangent (tan) as a function of frequency for host
(PZL), Cu2+
: PZL and Cr3+
: PZL glasses are shown.
From figure it is observed that dielectric loss of the
three studied glass system decreases with an increase
in frequency due to mobility of conducting species.
The higher the mobility of conducting species, the
higher would be the dielectric loss component [29].
The frequency (log f) dependent ac conductivity
(logac) profiles for host (PZL), Cu2+
: PZL and Cr3+
:
PZL glasses shown in Fig.8 are analyzed on the basis
of Jonscher universal power law [30]:
S
dc 0 < s < 1 ... (10)
where dc is the dc conductivity of the samples, A is
temperature dependent constant, 2 f is the
angular frequency of the applied field and s is the
power law exponent in the range 0 < s < 1, represents
the degree of interaction between the mobile ions The
frequency dependence of conductivity is sum of the
dc conductivity due to movements of free charges
and polarization conductivity (ac conductivity) due to
movements of bound charges.
Fig.8: Dependence of ac-conductivity (log ac) as
function of log (f) at room temperature for host PZL,
Cu2+
: PZL and Cr3+
: PZL glasses.
In Fig.8, from the profiles of frequency
dependence of ac conductivity, it is observed that, the
glass system with and without CuO and Cr2O3 as
dopant ions exhibit same trend of increasing in ac
conductivity as a function of frequency. It is also
observed that in the low frequency region, ion
conductivity low and frequency independent, which
could be attributed to the polarization effects at the
electrode-electrolyte interface, the accumulation of
ions due to slow periodic reversal of the electric field.
In the intermediate frequency region, conductivity is
a frequency independent due to a short range
transport of ions in response to electric field. In the
high frequency region, conductivity curves were
tending to merge into a single curve becoming
strongly frequency dependent. These curves show
almost a linear behaviour which follows a power law
relation in the higher frequency region:
S
s < 1 ... (11)
The exponent s can be measured by taking
slope of log ac versus log f for the curves from the
equation
acd Ln f
S
d Ln f
, found to lies in the
range of 0.7 to 0.9 which explains the interaction
between the mobile ions [31].
IV. CONCLUSION
In summary, it is concluded that we have
prepared transparent and stable optical glasses in the
chemical composition of 50P2O5-30ZnO-20LiF
(host), 0.5 mol % Cr2O3: 49.5P2O5-30ZnO-20LiF and
0.5 mol % CuO: 49.5P2O5-30ZnO-20LiF glasses by
employing melt quenching technique. Weight loss in
the host precursor chemical mix is noticed from its
TG profile whereas glass transition (Tg =375 °C) and
crystalline (Tc =500 °C) temperatures have been
identified from their DTA profile. Amorphous nature
of host glass has been confirmed from its XRD
profile and EDAX profiles of doped and undoped
(host) PZL glass provide evidence for elemental
analysis for all three chemical compositions glasses
studied. The absorption spectra of Cr2O3: PZL and
CuO: PZL glasses confirm that chromium exists in
Cr3+
state while copper exists in Cu2+
state in an
octotohedral site. From absorption spectra, local
symmetry and structural information of the
neighbouring atoms of dopant ions (Cr3+
& Cu2+
) have
been explained from their crystal field strength (Dq)
and energy level structures addressing Racah (B &
C) parameters. Both excitation and emission spectra
these two doped optical glasses have also been
analysed. The dielectric properties ( & tan) of
these glasses are found to be decreasing with an
increase in frequency due to accumulation of charges
at the electrode-electrolyte interface hence results in
with polarization effect.
7. C. Parthasaradhi Reddy et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 5), May 2014, pp.127-134
www.ijera.com 133 | P a g e
Due to the adding of transition metal ions
(Cr3+
or Cu2+
) into the chosen host glass matrix, their
ac (ac) conductivities are found to be significantly
enhanced in comparison with the host (PZL) glass.
Thus, we suggest that the present study has provided
us progressive outlook tend in carrying out further
exploration on these glasses to dope them with
several other transition metal ions as dopants to
evaluate their optical, dielectric and conductivity
performances for applications purpose.
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