IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Molecular Beam Epitaxial Growth and Dielectric Characterization of Ba0.6Sr0.4...Oleg Maksimov
The document summarizes research on growing and characterizing Ba0.6Sr0.4TiO3 thin films by molecular beam epitaxy on MgO and LaAlO3 substrates. Ba0.6Sr0.4TiO3 films were successfully grown epitaxially on both substrates as determined by in-situ RHEED analysis. However, ex-situ XRD and dielectric characterization found the film grown on LaAlO3 was of higher crystalline quality with a narrower rocking curve width and lower dielectric loss compared to the film on MgO. Dielectric constants of around 1300 were calculated for both films but the film on MgO had a significantly higher loss of 0.295 attributed to its lower crystalline quality
Structural Properties of (SnO2)1-x(ZnO)xThin Films Deposited By Spray Pyrolys...IJAEMSJORNAL
Nano structure of mixed (SnO2)1-x(ZnO)x thin films were prepared by spray pyrolysis technique at a substrate temperature of 400°C. The films deposited were 190 nm thickness. The XRD analysis for its structural characteristic has been performed. The average grain size was found to be between 21.27 and 15.80 nm.AFM Atomic Force microscope gives good information about the surface topography of the film.It is understood that the crystallinity of SnO2increases with increasing ZnO Vol.%.
Effect of Annealing on the Structural and Optical Properties of Nanostr...sarmad
Effect of Annealing on the Structural and Optical Properties of Nanostructured TiO2 Films Prepared By PLD. تأثير التلدين على الخواص التركيبية والبصرية لأغشية أوكسيد التيتانيوم (TiO2) ذات التراكيب النانوية المحضرة بتقنية ترسيب الليزر النبضي (PLD)
Rosa alejandra lukaszew tests of the gurenvich odel toward larger field gra...thinfilmsworkshop
SRF properties are inherently a surface phenomenon involving a material thickness of a few microns thus opening up the possibility of using thin film coatings to achieve a desired performance. I will describe our experimental attempts to test the superconducting/insulating/superconducting (SIS) multilayer model proposed by A. Gurevich [1] to shield the bulk of the cavity from vortex penetration and hence enable larger accelerating fields than presently possible.
Investigation of As-doped ZnO films synthesized via thermal annealing of ZnSe...Oleg Maksimov
The document summarizes research investigating As-doped ZnO films synthesized via thermal annealing of ZnSe/GaAs heterostructures. Key findings include:
1) XRD and Raman analysis showed the films were polycrystalline c-axis oriented ZnO containing nanometer-sized As clusters.
2) SEM images showed the surface consisted of dense, uniformly sized grains.
3) Photoluminescence spectra exhibited a sharp band edge emission line at 3.262 eV, indicating high optical quality.
4) Auger electron spectroscopy detected uniform As diffusion through the ZnO film and at the surface, suggesting As incorporation into the ZnO lattice.
The International Journal of Engineering and Sciencetheijes
The document summarizes research on the dielectric, magnetic, electric, and structural properties of Ni0.2-Cox-Zn0.8-x ferrite nanoparticles synthesized using a sol-gel auto combustion method. X-ray diffraction analysis showed the particles crystallized in the spinel ferrite structure. Scanning electron microscopy revealed the particles had compact structures smaller than 60 nm. Fourier transform infrared spectroscopy confirmed the presence of ferrite functional groups. Magnetic properties such as saturation magnetization increased with higher Co-Zn concentration. Dielectric properties varied with sintering temperature.
The document studied the effect of nitrogen on precipitation in an austenitic stainless steel used in orthopedic implants. It found that high nitrogen content led to precipitation of niobium nitrides in all annealing temperatures due to nitrogen's higher affinity for niobium than chromium. Two types of nitrides, chromium nitride and niobium nitride, were identified along with intermetallic phases Z and χ containing chromium, niobium, and molybdenum. The significant presence of nitrogen and niobium in the steel composition drove precipitation of these phases.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Molecular Beam Epitaxial Growth and Dielectric Characterization of Ba0.6Sr0.4...Oleg Maksimov
The document summarizes research on growing and characterizing Ba0.6Sr0.4TiO3 thin films by molecular beam epitaxy on MgO and LaAlO3 substrates. Ba0.6Sr0.4TiO3 films were successfully grown epitaxially on both substrates as determined by in-situ RHEED analysis. However, ex-situ XRD and dielectric characterization found the film grown on LaAlO3 was of higher crystalline quality with a narrower rocking curve width and lower dielectric loss compared to the film on MgO. Dielectric constants of around 1300 were calculated for both films but the film on MgO had a significantly higher loss of 0.295 attributed to its lower crystalline quality
Structural Properties of (SnO2)1-x(ZnO)xThin Films Deposited By Spray Pyrolys...IJAEMSJORNAL
Nano structure of mixed (SnO2)1-x(ZnO)x thin films were prepared by spray pyrolysis technique at a substrate temperature of 400°C. The films deposited were 190 nm thickness. The XRD analysis for its structural characteristic has been performed. The average grain size was found to be between 21.27 and 15.80 nm.AFM Atomic Force microscope gives good information about the surface topography of the film.It is understood that the crystallinity of SnO2increases with increasing ZnO Vol.%.
Effect of Annealing on the Structural and Optical Properties of Nanostr...sarmad
Effect of Annealing on the Structural and Optical Properties of Nanostructured TiO2 Films Prepared By PLD. تأثير التلدين على الخواص التركيبية والبصرية لأغشية أوكسيد التيتانيوم (TiO2) ذات التراكيب النانوية المحضرة بتقنية ترسيب الليزر النبضي (PLD)
Rosa alejandra lukaszew tests of the gurenvich odel toward larger field gra...thinfilmsworkshop
SRF properties are inherently a surface phenomenon involving a material thickness of a few microns thus opening up the possibility of using thin film coatings to achieve a desired performance. I will describe our experimental attempts to test the superconducting/insulating/superconducting (SIS) multilayer model proposed by A. Gurevich [1] to shield the bulk of the cavity from vortex penetration and hence enable larger accelerating fields than presently possible.
Investigation of As-doped ZnO films synthesized via thermal annealing of ZnSe...Oleg Maksimov
The document summarizes research investigating As-doped ZnO films synthesized via thermal annealing of ZnSe/GaAs heterostructures. Key findings include:
1) XRD and Raman analysis showed the films were polycrystalline c-axis oriented ZnO containing nanometer-sized As clusters.
2) SEM images showed the surface consisted of dense, uniformly sized grains.
3) Photoluminescence spectra exhibited a sharp band edge emission line at 3.262 eV, indicating high optical quality.
4) Auger electron spectroscopy detected uniform As diffusion through the ZnO film and at the surface, suggesting As incorporation into the ZnO lattice.
The International Journal of Engineering and Sciencetheijes
The document summarizes research on the dielectric, magnetic, electric, and structural properties of Ni0.2-Cox-Zn0.8-x ferrite nanoparticles synthesized using a sol-gel auto combustion method. X-ray diffraction analysis showed the particles crystallized in the spinel ferrite structure. Scanning electron microscopy revealed the particles had compact structures smaller than 60 nm. Fourier transform infrared spectroscopy confirmed the presence of ferrite functional groups. Magnetic properties such as saturation magnetization increased with higher Co-Zn concentration. Dielectric properties varied with sintering temperature.
The document studied the effect of nitrogen on precipitation in an austenitic stainless steel used in orthopedic implants. It found that high nitrogen content led to precipitation of niobium nitrides in all annealing temperatures due to nitrogen's higher affinity for niobium than chromium. Two types of nitrides, chromium nitride and niobium nitride, were identified along with intermetallic phases Z and χ containing chromium, niobium, and molybdenum. The significant presence of nitrogen and niobium in the steel composition drove precipitation of these phases.
This document summarizes a conference presentation on conducting polymer nanofibers and graphene. It discusses how polyacetylene nanofibers have intrinsic conductivity similar to metals. It also summarizes the 2010 Nobel Prize in Physics that was awarded for the discovery of graphene, a single layer of carbon atoms with unusual electronic properties. The document concludes by describing several methods for producing graphene sheets, including mechanical exfoliation of graphite and chemical vapor deposition.
Synthesis Of Nanostructured TiO2 Thin Films By Pulsed Laser Deposition (PLD) ...sarmad
Sarmad Sabih Al-Obaidi
Ali Ahmed Yousif
Abstract
In this work, nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates. TiO2 thin films then were annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structural and morphological were studied. Many growth parameters have been considered to specify the optimum conditions, namely substrate temperature (300 °C), oxygen pressure (10-2 Torr), laser fluence energy density (0.4 J/cm2), using double frequency Q-switching Nd:YAG laser beam (wavelength 532nm), repetition rate (1-6 Hz) and the pulse duration of 10 ns. The results of the X-ray test show that all nanostructures tetragonal are polycrystalline. These results show that grain size increase from 19.5 nm to 29.5 with the increase of annealing temperature. The XRD results also reveal that the deposited thin film, annealed at 400 °C of TiO2 have anatase phase. Thin films annealed at 500 °C and 600 °C have mixed anatase and rutile phases. Full Width at Half Maximum (FWHM) values of the (101) peaks of these films decrease from 0.450° to 0.301° with the increase of annealing temperature. Surface morphology of the thin films have been studied by using atomic force microscopes (AFM). AFM measurements confirmed that the films have good crystalline and homogeneous surface. The Root Mean Square (RMS) value of thin films surface roughness are increased with the increase of annealing temperature.
الخلاصة
على (PLD) النانویة بوساطة تقنیة ترسیب اللیزر النبضي (TiO في ھذا البحث، تم انماء أغشیة اوكسید التیتانیوم ( 2
الرقیقة من 400 الى 600 درجة مئویة في الھواء مدة ساعتین . ودرس تأثیر TiO قواعد زجاجیة. ومن ثم لدنت أغشیة 2
التلدین في الخصائص التركیبیة والطبوغرافیة. عوامل عدیدة لأنماء الأغشیة اخذت بنظر الاعتبار لتحدید الحالة المثلى مثل
0.4 ) باستخدام J/cm 10-2 ) ،كثافة طاقة الفیض اللیزري( 2 Torr) 300 ) ،ضغط الأوكسجین ºC) درجة حرارة القاعدة
532 بمعدل تكراریة - 1 nm التردد المضاعف للیزر النیدیمیوم- یاك الذي یعمل بتقنیة عامل النوعیة عند الطول الموجي
6 ھرتز) وامد نبضة 10 نانوثانیة. تظُھر نتائج فحوصات الأشعة السینیة أن جمیع التراكیب النانویة رباعیة متعددة )
التبلور. وان ھذه النتائج تظھر زیادة في حجم الحبیبات من 19.5 نانومتر الى 29.5 نانومترمع زیادة درجة حرارة التلدین.
نتائج الأشعة السینیة اظھرت ایضا ان الغشاء المرسب والملدن في 400 درجة مئویة لثنائي اوكسید
The document discusses the Air Force Office of Scientific Research (AFOSR) portfolio on aerospace materials for extreme environments. The portfolio aims to provide fundamental knowledge to enable advances in future Air Force technologies through discovering and characterizing materials that can withstand extreme environments involving mechanical, thermal, and electromagnetic loads. It covers theoretical and computational tools to aid materials discovery, physics and chemistry of materials in stressed environments, and experimental tools to address complexity from combined external fields in extreme conditions.
The document discusses several methods for determining the size of fine powder particles, including:
1. Calculating mean diameter based on measurements of individual particle sizes and accounting for polydispersity.
2. Using scanning electron microscopy and transmission electron microscopy to directly measure particle sizes.
3. Employing sedimentation techniques like photo-sedimentation and X-ray sedimentation, based on Stokes' equations, to determine particle size distributions.
4. Analyzing particle shapes using flow-based systems that inject a thin, monolayered stream of particles into a flow cell for microscopic imaging and size calculations.
This thesis examines the photochemical properties of single-walled carbon nanotube ozonides and α-azoxy ketones. Chapter 1 provides spectral and physical characterization of reference single-walled carbon nanotube samples. Chapter 2 studies the formation and decomposition kinetics of carbon nanotube ozonides, finding rates on the order of seconds and minutes, respectively. Chapter 3 analyzes the influence of ozonation on Raman spectra of single-walled carbon nanotubes. Chapter 4 uses infrared spectroscopy to study reactions of ozonated nanotubes. Chapter 5 examines how ozonated nanotubes react with electron-rich nucleophiles like amines and thiols. Chapter 6 explores trapping reactive
Study of Annealing Effect on the Some Physical Properties of Nanostructured T...sarmad
Ali A.Yousif ● , Sarmad S. Al-Obaidi ●●
Abstract
Nanostructured Titanium Dioxide (TiO2) thin films were prepared by pulsed
laser deposition (PLD) on the glass substrates. The effects of different annealing
temperature (400, 500 and 600 °C) towards the some physical properties such as
structural, morphological and optical have been studied. From X-ray diffraction
result, the crystallinity of TiO2 thin films improved at higher annealing
temperature. It also could be observed that the rutile phase start to exist at
annealing temperatures of 500 °C and 600 °C. The Full Width at Half
Maximum (FWHM) of the (101) peaks of these films decreases from 0.450° to
0.301° with increasing of annealing temperature. AFM measurements confirmed
that the films grown by this technique have good crystalline and homogeneous
surface. The Root Mean Square (RMS) value of thin films surface roughness
increased with increasing of the annealing temperature. From UV-VIS
spectrophotometer measurements, the optical transmission results shows that the transmission over than ~65% in the near-infrared region which decrease with the increasing of annealing temperatures. The allowed indirect optical band gap of the films was estimated to be in the range from 3.49 to 3.1 eV. The allowed direct band gap was found to decrease from 3.74 eV to 3.55 eV with the increase of annealing temperature. The refractive index of the films was found from 2.27 -2.98 at 550nm. The extinction coefficient, real and imaginary parts of the dielectric constant increase with annealing temperature.
This document summarizes a study that characterized carbon nanofibers (CNFs) with different functional groups through in situ tensile testing. It found that fluorinated CNFs possessed higher nominal strength but similar strain compared to pristine and amino-functionalized CNFs. All CNF types failed in a similar cup-cone fracture pattern. HRTEM revealed changes in the hollow core of fluorinated CNFs after fracture, attributed to fluorination-induced compressive forces. The study provides mechanical property data that can inform the use of CNFs as composite reinforcements.
1996 atomic force microscopy study of (001) sr tio3 surfacespmloscholte
The document summarizes an atomic force microscopy study of SrTiO3 surfaces after different heat treatments. The key points are:
1) Annealing in O3 results in atomically flat terraces separated by smooth, one unit cell high steps that follow the substrate's miscut orientation.
2) Annealing in O2 produces irregularly shaped terraces with step heights varying between 0.5-2.5 unit cells. Line defects and holes are also observed.
3) Depositing SrTiO3 on a surface annealed in O3 increases roughness due to island formation but heals line defects.
4) Annealing in UHV produces rougher steps and surface clusters, indicating a
This document discusses a lecture on advanced electronic materials processing. Specifically, it covers ceramic processing techniques for fabricating multilayer ceramic capacitors (MLCCs). Key topics include preparing high-purity ceramic powders, optimizing powder characteristics like size and dispersion for tape casting, and production processes like tape casting, printing, and lamination. The goal is to enable mass production of smaller 0402 size MLCCs using finer ceramic powders and more advanced processing methods.
The document summarizes two methods for synthesizing nanostructured ceramic powders: the mimic alkoxide method and hydrothermal synthesis.
The mimic alkoxide method involves dissolving a cerium precursor in alcohol and adding it dropwise to a precipitating solution, producing nanocrystalline powder with primary particles around 15nm that are well-sintered at lower temperatures than aqueous precipitation.
Hydrothermal synthesis uses high-temperature high-pressure water to precipitate oxides from precursor solutions, producing crystalline anhydrous powder without needing calcination or milling, and employing inexpensive raw materials. It is highlighted for making solid-solution particles for multilayer ceramic capacitors.
1. Porous hollow SnO2 nanofibers were fabricated by annealing electrospun polyvinylpyrrolidone (PVP)/Sn precursor composite nanofibers.
2. The formation mechanism involves a core-shell structure forming during electrospinning due to solvent evaporation. PVP then decomposes during annealing, acting as a sacrificial template to maintain the fibrous structure.
3. A Kirkendall effect and concentration gradient lead to hollow fiber formation as Sn precursor diffuses outward and SnO2 forms on the surface via surface diffusion, leaving a hollow core.
Improvement Structural and Optical Properties of ZnO/ PVA Nanocompositesiosrjce
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.
1997 nucleation of homoepitaxial si chains on si(001) at room temperaturepmloscholte
1) Si dimers initially adsorb at preferred sites on the Si(001) surface, with most occupying C-positions.
2) Interactions between dimers and diffusing adatoms lead to the formation of three-atom clusters like twins and crosses. These can extend into diluted lines of C dimers along [110] and [310] directions.
3) Upon further deposition, the diluted dimer lines transform into epitaxial dimer rows through a process starting at the line ends of reorienting dimers and adding mobile adatoms.
Rosa alejandra lukaszew a review of the thin film techniques potentially ap...thinfilmsworkshop
This document discusses thin film techniques that could be applicable for superconducting radio frequency (SRF) cavities. It reviews various thin film deposition methods like sputtering, evaporation, and ion beam assisted deposition. Challenges in achieving high quality niobium films for SRF cavities are discussed, including issues like adhesion, purity, defects, grain size, stress. The document provides background on thin film nucleation and growth processes. It also summarizes some previous work done on niobium thin films at the College of William and Mary using DC magnetron sputtering and reactive sputtering.
Aula com Exemplos de Aplicações.
Disciplina EMC5732 - Estrutura Cristalina de Solidos (/ Caracterização de Materiais 2), 2011/03, Prof. Ana Maria Maliska
Curso - Engenharia de Materiais
Departamento de Engenharia Mecânica
Universidade Federal de Santa Catarina
Iaetsd synthesis and characterization of in asIaetsd Iaetsd
This document summarizes research on the synthesis and characterization of InAsxN1-x ternary semiconductor thin films and nanostructures. Soft chemical methods like solvo thermal processes are used to produce size-tunable InAsxN1-x nanocrystals. Nanowires and nanorods of InAsxN1-x have also been obtained by solution-based and hydrothermal methods. Characterization with techniques such as TEM, SAED, XRD, and UV-Vis spectroscopy show the materials are highly crystalline with properties dependent on size and shape. The soft chemical routes demonstrated are effective for preparing semiconductor nanostructures of chalcogenides and nitrides.
The document describes methods for improving X-ray contrast of phases in porous rock samples using micro-CT imaging and image processing. Heavy metal ions are used to enhance the contrast of ice and clays. A Bruker micro-CT scanner with cooling stage is used to image ice-saturated rock samples. Image segmentation software Avizo Fire is applied to separate phases and calculate properties like porosity, permeability, and pore size distribution from the 3D digital models.
This document discusses several types of viscometers used to measure viscosity, including rotational viscometers, cone and plate viscometers, and falling ball viscometers. Rotational viscometers measure viscosity by sensing the torque resistance of a spindle rotating in a fluid sample at constant speeds. Cone and plate viscometers measure the torque required to rotate a cone in highly viscous fluids and pastes at varying angular velocities. Falling ball viscometers time the fall of a ball between marks in a temperature-controlled fluid sample to calculate viscosity.
1. The document discusses the synthesis of nanosized porous materials like BEA and LTA zeolites and preparation of metal-containing molecular sieves via methods like ion exchange followed by gamma irradiation or thermal reduction.
2. Pt and Cu clusters were incorporated into BEA zeolite via ion exchange and treated with gamma irradiation or plasma treatment to form metal clusters inside the zeolite pores. HRTEM showed the metal clusters were 1-2nm in size and located inside the zeolite channels.
3. The metal-doped zeolites were used to make thin films via spin coating. GI-XRD and ellipsometry showed the films had Pt clusters and thickness of 200-
The document summarizes key aspects of low-temperature co-fired ceramic (LTCC) technology for applications in radio frequency (RF) modules. It discusses how LTCC enables miniaturization through multi-layer integration at lower costs than other technologies like thin film. Specific advantages highlighted include high density packaging, parallel processing for shorter development times, design flexibility through buried passive components, and compatibility with various conductors and materials for resistors and capacitors suitable for co-firing. Process details covered include via formation, conductor printing, lamination, and sintering around 850°C to enable silver electrodes. Example applications and performance metrics are also summarized.
This document provides an introduction to elliptic curve cryptography. It discusses how elliptic curves can be used for digital signatures and key agreement. It also describes the implementation of elliptic curve cryptography over finite fields, prime fields, and binary fields. The document gives an overview of elliptic curve point addition and scalar multiplication. It explains the elliptic curve discrete logarithm problem, which the security of elliptic curve cryptography depends on.
This document summarizes a research paper that proposes using complex wavelet transform (CWT) with a custom thresholding algorithm to estimate Doppler profiles from MST radar signals. CWT has advantages over real wavelet transforms by generating complex coefficients. The custom thresholding function is continuous around the threshold and can be adapted to signal characteristics. The algorithm applies CWT thresholding to the radar signal spectrum before Doppler estimation. Results on test radar data show the method can estimate Doppler at higher altitudes where noise dominates, unlike existing techniques.
This document summarizes a conference presentation on conducting polymer nanofibers and graphene. It discusses how polyacetylene nanofibers have intrinsic conductivity similar to metals. It also summarizes the 2010 Nobel Prize in Physics that was awarded for the discovery of graphene, a single layer of carbon atoms with unusual electronic properties. The document concludes by describing several methods for producing graphene sheets, including mechanical exfoliation of graphite and chemical vapor deposition.
Synthesis Of Nanostructured TiO2 Thin Films By Pulsed Laser Deposition (PLD) ...sarmad
Sarmad Sabih Al-Obaidi
Ali Ahmed Yousif
Abstract
In this work, nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates. TiO2 thin films then were annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structural and morphological were studied. Many growth parameters have been considered to specify the optimum conditions, namely substrate temperature (300 °C), oxygen pressure (10-2 Torr), laser fluence energy density (0.4 J/cm2), using double frequency Q-switching Nd:YAG laser beam (wavelength 532nm), repetition rate (1-6 Hz) and the pulse duration of 10 ns. The results of the X-ray test show that all nanostructures tetragonal are polycrystalline. These results show that grain size increase from 19.5 nm to 29.5 with the increase of annealing temperature. The XRD results also reveal that the deposited thin film, annealed at 400 °C of TiO2 have anatase phase. Thin films annealed at 500 °C and 600 °C have mixed anatase and rutile phases. Full Width at Half Maximum (FWHM) values of the (101) peaks of these films decrease from 0.450° to 0.301° with the increase of annealing temperature. Surface morphology of the thin films have been studied by using atomic force microscopes (AFM). AFM measurements confirmed that the films have good crystalline and homogeneous surface. The Root Mean Square (RMS) value of thin films surface roughness are increased with the increase of annealing temperature.
الخلاصة
على (PLD) النانویة بوساطة تقنیة ترسیب اللیزر النبضي (TiO في ھذا البحث، تم انماء أغشیة اوكسید التیتانیوم ( 2
الرقیقة من 400 الى 600 درجة مئویة في الھواء مدة ساعتین . ودرس تأثیر TiO قواعد زجاجیة. ومن ثم لدنت أغشیة 2
التلدین في الخصائص التركیبیة والطبوغرافیة. عوامل عدیدة لأنماء الأغشیة اخذت بنظر الاعتبار لتحدید الحالة المثلى مثل
0.4 ) باستخدام J/cm 10-2 ) ،كثافة طاقة الفیض اللیزري( 2 Torr) 300 ) ،ضغط الأوكسجین ºC) درجة حرارة القاعدة
532 بمعدل تكراریة - 1 nm التردد المضاعف للیزر النیدیمیوم- یاك الذي یعمل بتقنیة عامل النوعیة عند الطول الموجي
6 ھرتز) وامد نبضة 10 نانوثانیة. تظُھر نتائج فحوصات الأشعة السینیة أن جمیع التراكیب النانویة رباعیة متعددة )
التبلور. وان ھذه النتائج تظھر زیادة في حجم الحبیبات من 19.5 نانومتر الى 29.5 نانومترمع زیادة درجة حرارة التلدین.
نتائج الأشعة السینیة اظھرت ایضا ان الغشاء المرسب والملدن في 400 درجة مئویة لثنائي اوكسید
The document discusses the Air Force Office of Scientific Research (AFOSR) portfolio on aerospace materials for extreme environments. The portfolio aims to provide fundamental knowledge to enable advances in future Air Force technologies through discovering and characterizing materials that can withstand extreme environments involving mechanical, thermal, and electromagnetic loads. It covers theoretical and computational tools to aid materials discovery, physics and chemistry of materials in stressed environments, and experimental tools to address complexity from combined external fields in extreme conditions.
The document discusses several methods for determining the size of fine powder particles, including:
1. Calculating mean diameter based on measurements of individual particle sizes and accounting for polydispersity.
2. Using scanning electron microscopy and transmission electron microscopy to directly measure particle sizes.
3. Employing sedimentation techniques like photo-sedimentation and X-ray sedimentation, based on Stokes' equations, to determine particle size distributions.
4. Analyzing particle shapes using flow-based systems that inject a thin, monolayered stream of particles into a flow cell for microscopic imaging and size calculations.
This thesis examines the photochemical properties of single-walled carbon nanotube ozonides and α-azoxy ketones. Chapter 1 provides spectral and physical characterization of reference single-walled carbon nanotube samples. Chapter 2 studies the formation and decomposition kinetics of carbon nanotube ozonides, finding rates on the order of seconds and minutes, respectively. Chapter 3 analyzes the influence of ozonation on Raman spectra of single-walled carbon nanotubes. Chapter 4 uses infrared spectroscopy to study reactions of ozonated nanotubes. Chapter 5 examines how ozonated nanotubes react with electron-rich nucleophiles like amines and thiols. Chapter 6 explores trapping reactive
Study of Annealing Effect on the Some Physical Properties of Nanostructured T...sarmad
Ali A.Yousif ● , Sarmad S. Al-Obaidi ●●
Abstract
Nanostructured Titanium Dioxide (TiO2) thin films were prepared by pulsed
laser deposition (PLD) on the glass substrates. The effects of different annealing
temperature (400, 500 and 600 °C) towards the some physical properties such as
structural, morphological and optical have been studied. From X-ray diffraction
result, the crystallinity of TiO2 thin films improved at higher annealing
temperature. It also could be observed that the rutile phase start to exist at
annealing temperatures of 500 °C and 600 °C. The Full Width at Half
Maximum (FWHM) of the (101) peaks of these films decreases from 0.450° to
0.301° with increasing of annealing temperature. AFM measurements confirmed
that the films grown by this technique have good crystalline and homogeneous
surface. The Root Mean Square (RMS) value of thin films surface roughness
increased with increasing of the annealing temperature. From UV-VIS
spectrophotometer measurements, the optical transmission results shows that the transmission over than ~65% in the near-infrared region which decrease with the increasing of annealing temperatures. The allowed indirect optical band gap of the films was estimated to be in the range from 3.49 to 3.1 eV. The allowed direct band gap was found to decrease from 3.74 eV to 3.55 eV with the increase of annealing temperature. The refractive index of the films was found from 2.27 -2.98 at 550nm. The extinction coefficient, real and imaginary parts of the dielectric constant increase with annealing temperature.
This document summarizes a study that characterized carbon nanofibers (CNFs) with different functional groups through in situ tensile testing. It found that fluorinated CNFs possessed higher nominal strength but similar strain compared to pristine and amino-functionalized CNFs. All CNF types failed in a similar cup-cone fracture pattern. HRTEM revealed changes in the hollow core of fluorinated CNFs after fracture, attributed to fluorination-induced compressive forces. The study provides mechanical property data that can inform the use of CNFs as composite reinforcements.
1996 atomic force microscopy study of (001) sr tio3 surfacespmloscholte
The document summarizes an atomic force microscopy study of SrTiO3 surfaces after different heat treatments. The key points are:
1) Annealing in O3 results in atomically flat terraces separated by smooth, one unit cell high steps that follow the substrate's miscut orientation.
2) Annealing in O2 produces irregularly shaped terraces with step heights varying between 0.5-2.5 unit cells. Line defects and holes are also observed.
3) Depositing SrTiO3 on a surface annealed in O3 increases roughness due to island formation but heals line defects.
4) Annealing in UHV produces rougher steps and surface clusters, indicating a
This document discusses a lecture on advanced electronic materials processing. Specifically, it covers ceramic processing techniques for fabricating multilayer ceramic capacitors (MLCCs). Key topics include preparing high-purity ceramic powders, optimizing powder characteristics like size and dispersion for tape casting, and production processes like tape casting, printing, and lamination. The goal is to enable mass production of smaller 0402 size MLCCs using finer ceramic powders and more advanced processing methods.
The document summarizes two methods for synthesizing nanostructured ceramic powders: the mimic alkoxide method and hydrothermal synthesis.
The mimic alkoxide method involves dissolving a cerium precursor in alcohol and adding it dropwise to a precipitating solution, producing nanocrystalline powder with primary particles around 15nm that are well-sintered at lower temperatures than aqueous precipitation.
Hydrothermal synthesis uses high-temperature high-pressure water to precipitate oxides from precursor solutions, producing crystalline anhydrous powder without needing calcination or milling, and employing inexpensive raw materials. It is highlighted for making solid-solution particles for multilayer ceramic capacitors.
1. Porous hollow SnO2 nanofibers were fabricated by annealing electrospun polyvinylpyrrolidone (PVP)/Sn precursor composite nanofibers.
2. The formation mechanism involves a core-shell structure forming during electrospinning due to solvent evaporation. PVP then decomposes during annealing, acting as a sacrificial template to maintain the fibrous structure.
3. A Kirkendall effect and concentration gradient lead to hollow fiber formation as Sn precursor diffuses outward and SnO2 forms on the surface via surface diffusion, leaving a hollow core.
Improvement Structural and Optical Properties of ZnO/ PVA Nanocompositesiosrjce
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.
1997 nucleation of homoepitaxial si chains on si(001) at room temperaturepmloscholte
1) Si dimers initially adsorb at preferred sites on the Si(001) surface, with most occupying C-positions.
2) Interactions between dimers and diffusing adatoms lead to the formation of three-atom clusters like twins and crosses. These can extend into diluted lines of C dimers along [110] and [310] directions.
3) Upon further deposition, the diluted dimer lines transform into epitaxial dimer rows through a process starting at the line ends of reorienting dimers and adding mobile adatoms.
Rosa alejandra lukaszew a review of the thin film techniques potentially ap...thinfilmsworkshop
This document discusses thin film techniques that could be applicable for superconducting radio frequency (SRF) cavities. It reviews various thin film deposition methods like sputtering, evaporation, and ion beam assisted deposition. Challenges in achieving high quality niobium films for SRF cavities are discussed, including issues like adhesion, purity, defects, grain size, stress. The document provides background on thin film nucleation and growth processes. It also summarizes some previous work done on niobium thin films at the College of William and Mary using DC magnetron sputtering and reactive sputtering.
Aula com Exemplos de Aplicações.
Disciplina EMC5732 - Estrutura Cristalina de Solidos (/ Caracterização de Materiais 2), 2011/03, Prof. Ana Maria Maliska
Curso - Engenharia de Materiais
Departamento de Engenharia Mecânica
Universidade Federal de Santa Catarina
Iaetsd synthesis and characterization of in asIaetsd Iaetsd
This document summarizes research on the synthesis and characterization of InAsxN1-x ternary semiconductor thin films and nanostructures. Soft chemical methods like solvo thermal processes are used to produce size-tunable InAsxN1-x nanocrystals. Nanowires and nanorods of InAsxN1-x have also been obtained by solution-based and hydrothermal methods. Characterization with techniques such as TEM, SAED, XRD, and UV-Vis spectroscopy show the materials are highly crystalline with properties dependent on size and shape. The soft chemical routes demonstrated are effective for preparing semiconductor nanostructures of chalcogenides and nitrides.
The document describes methods for improving X-ray contrast of phases in porous rock samples using micro-CT imaging and image processing. Heavy metal ions are used to enhance the contrast of ice and clays. A Bruker micro-CT scanner with cooling stage is used to image ice-saturated rock samples. Image segmentation software Avizo Fire is applied to separate phases and calculate properties like porosity, permeability, and pore size distribution from the 3D digital models.
This document discusses several types of viscometers used to measure viscosity, including rotational viscometers, cone and plate viscometers, and falling ball viscometers. Rotational viscometers measure viscosity by sensing the torque resistance of a spindle rotating in a fluid sample at constant speeds. Cone and plate viscometers measure the torque required to rotate a cone in highly viscous fluids and pastes at varying angular velocities. Falling ball viscometers time the fall of a ball between marks in a temperature-controlled fluid sample to calculate viscosity.
1. The document discusses the synthesis of nanosized porous materials like BEA and LTA zeolites and preparation of metal-containing molecular sieves via methods like ion exchange followed by gamma irradiation or thermal reduction.
2. Pt and Cu clusters were incorporated into BEA zeolite via ion exchange and treated with gamma irradiation or plasma treatment to form metal clusters inside the zeolite pores. HRTEM showed the metal clusters were 1-2nm in size and located inside the zeolite channels.
3. The metal-doped zeolites were used to make thin films via spin coating. GI-XRD and ellipsometry showed the films had Pt clusters and thickness of 200-
The document summarizes key aspects of low-temperature co-fired ceramic (LTCC) technology for applications in radio frequency (RF) modules. It discusses how LTCC enables miniaturization through multi-layer integration at lower costs than other technologies like thin film. Specific advantages highlighted include high density packaging, parallel processing for shorter development times, design flexibility through buried passive components, and compatibility with various conductors and materials for resistors and capacitors suitable for co-firing. Process details covered include via formation, conductor printing, lamination, and sintering around 850°C to enable silver electrodes. Example applications and performance metrics are also summarized.
This document provides an introduction to elliptic curve cryptography. It discusses how elliptic curves can be used for digital signatures and key agreement. It also describes the implementation of elliptic curve cryptography over finite fields, prime fields, and binary fields. The document gives an overview of elliptic curve point addition and scalar multiplication. It explains the elliptic curve discrete logarithm problem, which the security of elliptic curve cryptography depends on.
This document summarizes a research paper that proposes using complex wavelet transform (CWT) with a custom thresholding algorithm to estimate Doppler profiles from MST radar signals. CWT has advantages over real wavelet transforms by generating complex coefficients. The custom thresholding function is continuous around the threshold and can be adapted to signal characteristics. The algorithm applies CWT thresholding to the radar signal spectrum before Doppler estimation. Results on test radar data show the method can estimate Doppler at higher altitudes where noise dominates, unlike existing techniques.
This document summarizes a research paper that proposes a method for converting images and video into portraits and animations using RGB color segmentation. The method involves several steps: edge detection using Sobel operator, blurring the image with Gaussian blur to reduce noise, color segmentation by comparing RGB pixel values to a threshold, and region filling to convert the image into a portrait. The overall goal is to automatically convert still images and video into animated portraits without requiring design of characters or additional software.
This document summarizes a research paper that proposes a microcontroller-based cryptosystem using the Tiny Encryption Algorithm (TEA) combined with a Key Generation Unit (KGU). The KGU uses timers in the microcontroller to generate random bits for encryption keys. The cryptosystem can operate in serial or wireless transmission modes. Performance analysis shows the cryptosystem has improved throughput and decreased execution time compared to TEA alone. Randomness testing of the generated keys indicates distinct random bits. In conclusion, the system provides moderate security and simplicity for applications requiring secured data transfer with low cost and memory constraints.
Tener un bebé representa la decisión de Dios de que el mundo continúe, es el acto más maravillosamente irracional de dos personas enamoradas, y supone asumir la mayor responsabilidad y alegría que da la naturaleza.
Este documento habla sobre informática, definiendo la informática como la ciencia que estudia el tratamiento automático de la información mediante máquinas electrónicas. Distingue entre hardware, que son los elementos físicos del ordenador, y software, que son los programas que dirigen las tareas del ordenador. Enumera los principales componentes del hardware y software.
La guía explica cómo publicar en SlideShare indicando que los usuarios deben ingresar a la página web de SlideShare, registrarse si son nuevos o iniciar sesión si ya tienen una cuenta, y luego publicar sus presentaciones y documentos.
Este documento discute las ventajas e inconvenientes del uso de portafolios de evidencia. Entre las ventajas se encuentran que permite el aprendizaje cooperativo entre estudiantes y profesores, fomenta la autodisciplina y responsabilidad en los estudiantes, y permite la autoevaluación. Las desventajas incluyen que requiere mucho tiempo si no se establecen claramente los objetivos de aprendizaje y puede resultar en material innecesario. El documento concluye que los portafolios permiten ver las fortalezas y debilidades de
O documento fornece uma introdução aos estudos literários, definindo literatura como uma imitação da realidade através da palavra e explorando suas funções, como evasão, jogo e compromisso social. Também discute elementos como gêneros literários, cânone, diferenças entre textos literários e não literários, e aspectos técnicos da versificação como métrica e rima.
Este documento resume la historia de cómo un niño llamado Ken encuentra a una criatura legendaria llamada Shiron en una cueva misteriosa. Shiron es un dragón que puede transformarse en una rata y le explica a Ken sobre los legendz, criaturas poderosas como dragones. Sin embargo, al tocar una lápida misteriosa, liberan a otro dragón llamado Ranshiin, el enemigo de Shiron. Ahora Ken y Shiron deberán enfrentar las aventuras y peligros que se avecinan.
Este documento describe el Parque Nacional Los Glaciares, ubicado en la Patagonia argentina. El parque se extiende por 705.000 hectáreas en las provincias de Neuquén y Río Negro. La intendencia del parque se encuentra en San Carlos de Bariloche, accesible por varias rutas desde San Martín de los Andes, Neuquén y otras ciudades. El clima es seco pero las aguas del Lago Argentino y las laderas al sur crean un microclima más benigno que las mesetas circundantes, con días claros
Las leyes que regulan las franquicias en Venezuela incluyen la Constitución, que protege el derecho a dedicarse a la actividad económica de preferencia, el Código Civil, que establece los principios para los contratos y las obligaciones entre partes, y las leyes laborales como la Ley del Trabajo, que rigen la contratación de personal para actividades mercantiles independientes.
Este documento presenta un resumen de la Norma ISO 27001 sobre la gestión de la seguridad de la información. Explica que la norma establece los requisitos para implementar un sistema de gestión de seguridad de la información basado en el modelo Plan-Do-Check-Act. También describe los principales componentes de dicho sistema como el análisis de riesgos, los controles y la documentación requerida. Finalmente, resume los beneficios de la certificación ISO 27001 para las organizaciones.
O documento discute estratégias para integrar com sucesso pessoas com deficiência no local de trabalho, incluindo a remoção de barreiras físicas e atitudes, e os benefícios de contratar pessoas com deficiência.
Os alunos da Turma 3001 apresentaram poemas em forma de teatro. Durante a apresentação, um aluno pediu uma colega em casamento, causando emoção. A professora e diretora elogiaram a apresentação.
El documento explica qué es un sistema operativo y describe sus principales funciones como la administración de tareas, archivos y recursos. Explica que los sistemas operativos han evolucionado a través de cuatro generaciones, desde los primeros sistemas sin sistema operativo hasta los actuales que permiten el procesamiento en red. También menciona algunos de los sistemas operativos más comunes como MS-DOS, Windows, Unix y Linux.
1) Eneas huyó de Troya después de su destrucción y fundó la ciudad prometida por los dioses en Lacio.
2) Los gemelos Rómulo y Rémulo fundaron la ciudad de Roma.
3) La monarquía romana fue la primera forma de gobierno en Roma desde su fundación en el 753 a.C. hasta que la república fue establecida en el 509 a.C.
Este documento describe los conceptos básicos de la flexión pura. Explica que la flexión pura ocurre cuando un cuerpo está sujeto a dos momentos iguales y opuestos. También describe que en la flexión pura solo hay momento como fuerza interna y es constante a lo largo del elemento. Además, explica que el esfuerzo máximo en flexión pura ocurre en las fibras más alejadas del eje neutro y que su valor depende del momento y las propiedades de la sección transversal.
Un blog es un sitio web personal donde uno puede publicar fácilmente contenido sobre cualquier tema de manera regular. Generalmente los blogs se organizan en entradas con fecha que incluyen texto e imágenes. Estas entradas permiten comentarios de lectores y enlaces a otras fuentes, convirtiendo a los blogs y sus autores en participantes importantes de conversaciones en línea. Un blog puede usarse para compartir opiniones, noticias, diarios personales u otros fines según el autor lo desee.
Characterization of different dopants in TiO2 Structure by Pulsed Laser Dep...sarmad
Characterization of different dopants in TiO2 Structure by Pulsed Laser Deposition
A thesis submitted By: Khaled Z.Yahya
Supervised by: Prof.Dr. Adawiya J.Haider Prof.Dr. Raad M.S.Al-Haddad
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.
This document summarizes a study on the preparation and photoluminescent properties of Si nanocrystal-SiOX films deposited by reactive evaporation. Specifically:
- Films with varying oxygen concentration and Si crystallite size were produced by changing substrate temperature and oxygen partial pressure during Si or SiO evaporation.
- Only films prepared by evaporating SiO in an oxygen atmosphere exhibited room-temperature photoluminescence.
- X-ray diffraction, X-ray photoelectron spectroscopy, and infrared spectroscopy were used to analyze the film structures and compositions.
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.
Poster_SheongWei_NG_ Influence of Nanoparticles on Corrosion Resistance of El...SheongWei NG
This document discusses research on improving the corrosion resistance of electrodeposited Zn-Ni coatings on steel by incorporating nanoparticles (NPs). It finds that doping Zn-Ni coatings with TiO2 or SiO2 NPs creates a physical barrier that isolates the coating and improves corrosion resistance. The concentration of TiO2 NPs also affects morphology and corrosion resistance, with an optimal concentration of 5g/l TiO2 NPs found to give the lowest corrosion current. Higher concentrations can cause cracking and reduce corrosion resistance. Electrodeposition is described as a suitable coating method for producing these Zn-Ni-NP composite coatings.
This document summarizes research on using laser processing techniques to deposit nanocrystalline titanium dioxide (nc-TiO2) films for use in dye-sensitized solar cells. Pulsed laser deposition was used to deposit a dense TiO2 layer and laser direct-write was used to deposit porous nc-TiO2 layers of varying thickness. Solar cells made with laser-processed nc-TiO2 layers showed a power conversion efficiency of up to 4.3% under solar illumination. Thicker nc-TiO2 layers increased short circuit current but decreased open circuit voltage, due to increased recombination losses. Laser processing techniques allow conformal deposition of nc-TiO2 without masks or additional patterning steps.
Zinc Oxide–Titania Heterojunction-based Solid Nanospheres as Photoanodes for ...Devika Laishram
Agile nanostructure architectures and smart combinations of
semiconducting metal oxide materials are key features of
high-performing dye-sensitized solar cells (DSSCs). Herein,
we synthesize mesoporous solid nanospheres of ZnO–TiO2
with type-II heterojunction and use these as an efficient photoanode material for excellent photoconversion. These polydisperse aggregates doped with 1%, 5%, and 10% of ZnO
exhibit improved solar cell performance with respect to pristine TiO2 under AM 1.5 G. The 1% ZnO doped TiO2 nanosphere possess high specific surface area (84.23 m2
g
@1
) as
a photoanode and shows high photoconversion efficiency of
about 8.07% with ca. 18% improvement in the photocurrent
density (Jsc) compare to TiO2 nanosphere. The improved
solar cell performance (Dh=40%) of ZnO decorated TiO2
nanospheres is ascribed to type-II heterojunction of ZnO–
TiO2
, that reduces the electron recombination and synergistically enhances the electron mobility and charge collection
capability
Thermal annealing influence on spectral responsivity and specific detectivity...Muhammid Al-Baghdadi
This document summarizes research on the effects of thermal annealing on the spectral responsivity and specific detectivity of Al/NiO/PSi/Si/Al photodetectors. NiO nanoparticles were deposited on porous silicon (PSi) substrates via drop casting and annealed at 250°C and 500°C. X-ray diffraction analysis showed the NiO formed a cubic crystal structure. Annealing increased the NiO grain size and decreased the bandgap. Atomic force microscopy images showed annealed films had larger, more homogeneous grains. Photoluminescence measurements demonstrated light emission from the PSi layer. The spectral responsivity and specific detectivity of the photodetectors increased after annealing, indicating improved performance of
Effect of Sn Doping on Structural and Electrical Properties of ZnO Thin Films...journal ijrtem
Abstract: Un-doped and tin (Sn) doped ZnO films were deposited on heated glass substrates by chemical spray pyrolysis method
(CSP). The effect of Sn concentration on the structural, surface morphological and electrical properties of the SnO2 films was
investigated. XRD analyses showed that the obtained films are polycrystalline in nature with hexagonal structure with preferred
orientation of (101). Doping with tin (Sn) causes increase in the grain size. Atomic force microscopy images showed that the root
mean square of the average surface roughness's varied from (1.48 to 3.58) as dopant concentration increased from 0 to 5 wt.%. The
electrical properties of the Sn ZnO films were strongly influenced by doping concentration. The electrical resistance of the films was
sharply decreased as dopant concentration increased.
Keywords: (ZnO) thin films, Sn Doping, Structural and electrical Properties
Effect of Temperature on Structural, Morphological and Optical Properties of ...RSIS International
The Pure zinc oxide (ZnO) thin films of different substrate temperature have been prepared on well cleaned glass substrate by improved spray pyrolysis technique. The gross structure of the annealed films have been examined by X- ray diffraction (XRD) technique using powder X- ray diffractometer which reveals the enhancement of crystallinity with increase in the deposition temperature. Surface morphology of the synthesized ZnO thin films have been analyzed by means of atomic force microscopy (AFM) which reveals average particle size of as synthesize ZnO thin films has been found to be 79 nm. The band gap as deposited ZnO have been examined by UV-Vis spectroscopy carried out in absorption mode by Double Beam UV- VIS Spectrophotometer with radiations in the range of 훌= 190 nm to 1100 nm which is in the range of 3.03 eV to 3.16 eV.
This document summarizes the synthesis and characterization of thin films of pure TiO2 and Sr-doped TiO2 prepared by spin coating technique. Transparent thin films were prepared on glass substrates and annealed at different temperatures from 3000C to 6000C. Structural analysis using GIXRD and Raman spectroscopy confirmed the anatase phase of TiO2. AFM showed a homogeneous globular surface morphology. UV-Vis analysis demonstrated that the optical band gap increased with higher annealing temperatures. Photoluminescence study showed variation in emission peaks for different annealing temperatures and Sr concentrations. Electrical, gas sensing, wettability and self-cleaning properties were also investigated.
1. Nickel ions were implanted into alpha alumina single crystals using ion implantation to form nickel nanoparticles.
2. Transmission electron microscopy and X-ray photoelectron spectroscopy showed that the nickel nanoparticles formed were spherical and around 1-5 nm in diameter, and existed in the metallic nickel state.
3. Optical absorption spectroscopy revealed a broadband absorption peak at 400 nm attributed to surface plasmon resonance of the metallic nickel nanoparticles.
Optical properties of metallic nanoparticles in Ni-ion-implanted α-Al2O3 sing...Younes Sina
1. Nickel ions were implanted into alpha alumina single crystals using ion implantation to form nickel nanoparticles.
2. Transmission electron microscopy and X-ray photoelectron spectroscopy showed that the nickel nanoparticles formed were spherical and around 1-5 nm in diameter, and existed in the metallic nickel state.
3. Optical absorption spectroscopy revealed a broadband absorption peak at 400 nm attributed to surface plasmon resonance of the metallic nickel nanoparticles.
This document discusses composite layers in the Ni-P system containing TiO2 and PTFE. Specifically:
1. Composite Ni-P-TiO2 and Ni-P-TiO2-PTFE layers were prepared by electrodepositing nickel and titanium dioxide with additions of PTFE on a copper substrate.
2. The phase composition and surface morphology of the layers were examined using X-ray diffraction and microscopy. The volume fraction and size of TiO2 and PTFE particles in the layers were determined.
3. It was found that the presence of PTFE reduced the mean area of embedded TiO2 particles in the Ni-P-TiO2-PTFE layers compared to the TiO2
final accept-Optical and structural properties of TiO2 nanopowders with Co-Ce...nasrollah najibi ilkhchy
This document discusses a study on the optical and structural properties of TiO2 nanopowders doped with 2 mol% cerium and 4 mol% cobalt. X-ray diffraction analysis showed that cerium doping inhibited the formation of the rutile phase of titanium dioxide and promoted retention of the anatase phase at higher calcination temperatures. Optical absorption spectroscopy indicated that doping reduced the band gap of titanium dioxide from 3.21 eV to 3.14-3.20 eV. The crystallite size decreased with doping while the surface area increased compared to undoped titanium dioxide.
This document summarizes research on nanocrystalline titania powders doped with copper. Key findings include:
- Copper doping affected the phase stability of titania, promoting the rutile phase at higher temperatures.
- The 5% copper-doped titania sample had the largest degradation of methylene orange dye under visible light, indicating better photocatalytic activity than pure titania.
- UV-Vis spectroscopy estimated the band gap of the copper-doped titania to be 1.9-2 eV, lower than pure titania and allowing absorption of visible light.
Structural, Dielectric and Optical properties of Sputtered TiO2 nano-filmsIOSR Journals
Thin films of TiO2 were deposited on quartz and p-Si (100) substrates held at room temperature by sputtering of titanium target at various sputter powers in the range 80 - 200 W. The as-deposited films were annealed in air for an hour at 1023 K. The annealed films were characterized by using Fourier transform infra red spectroscopy, X-ray diffraction, Surface morphology, dielectric and optical properties. The deposition rate of the films increased from 1.26 to 6.66 nm/min. with increase of sputter power from 80 to 200 W. TiO2 films formed at sputter power of 80 W and annealed at 1023 K were polycrystalline in nature with anatase phase crystallite size of 40 nm, dielectric constant of 10, optical band gap of 3.65 eV and refractive index 2.35.
An effect of synthesis parameters on structural properties of AlN thin films ...IJASCSE
This document summarizes research on the effect of synthesis parameters on the structural properties of aluminum nitride (AlN) thin films deposited on metal substrates using DC sputtering.
Key findings include:
1) X-ray diffraction analysis showed the films had mixed cubic and hexagonal phases. Cubic phases were more prominent on copper substrates and increased with higher sputtering power and nitrogen gas flow.
2) Crystallite size, dislocation density, residual stress, and strain of the AlN films varied based on the sputtering power, gas ratio, and substrate material used. Optimal properties were observed for films deposited at 300W power and an Ar:N2 ratio of 14:6.
An effect of synthesis parameters on structural properties of AlN thin films ...
Km2518391842
1. Y.V.Subba Rao, B.S.Gangadhara, E.Suresh Babu, K.S.Sumana/ International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.1839-1842
Structural And Material Properties Of Ti-Si-N Nanocomposite
Coatings
Y.V.Subba Rao a,b,c B.S.Gangadharab, E.Suresh Babuc ,K.S.Sumanad
a
MRC-A.P.E.Research Lab, Materials Research Centre, Indian Institute of Science, Bangalore-12,India
b
Nanosys India, Bangalore-76, India,
c
A.P.E. Research S.r.l, Area Science Park, Basovizza, s.s. 14, Km 163,5 ,34149, Trieste,Italy,
d
Department of Physics, Maharani’s Science College, Palace Road, Bangalore, India.
ABSTRACT
In this paper Ti-Si-N nanocomposite Ti-Si-N nanocomposite coatings were deposited on
coatings were prepared by reactive magnetron different substrates by reactive DC magnetron
sputtering on to different substrates at different sputtering deposition unit HIND HIVAC. the
power 50, 100, 150 and 200 watt at substrate substrate temperature was 400oC High purity argon
temperature 400o. The presence of different was fed into the vacuum chamber for the plasma
phases like TiN, TiO2 and SiN were confirmed by generation. The substrates were etched for 5 min at
XPS analysis. From XRD analyses results, Ti–Si– a DC power of 50 W and an argon pressure of 10-
6
N nanocomposite coatings are mainly composed Torr (1.33X 10-4Pa). High purity (99.99%) T i and
of amorphous Si3N4 and TiN crystals with a grain Si targets of 7.5 cm diameter was used as cathodes.
size of 16 -30 nm. The Ti–Si–N coatings have The deposition parameters for Ti-Si-N sputtering are
somewhat mixed orientations (1 1 1), (2 2 0) and summarized in Table 2.1
(2 0 0). The intensity of the (2 0 0) peak decreases
with increasing in the content of power. The 2.1.Deposition parameters for Ti-Si-N
Topography and roughness parameter obtained nanocomposite coatings.
using AFM and resistive properties using four Table 2.1.Deposition parameters for Ti-Si-N
probe method.
Objects Specification
Keywords – Coatings, Nanocomposites,
Sputtering, Si and Ti Target (2”Dia) Ti & Si
Substrate Glass, Si wafer, 316L Stainless steel
1. INTRODUCTION Target to substrate distance 60 mm
In recent years usage of hard coatings using Ultimate vacuum 1 x 10-6 m bar
Ti-Si-N have great importance for metal cutting and Operating vacuum 2 x 10-3 m bar
machine tool applications. It plays prominent role in Sputtering gas (Ar: N2) 2: 1
industrial applications because of its high hardness, Power 50, 100, 150, 200 W
high temperature resistance, good wear and Substrate temperature 400 C
chemical stability [1-5] .Generally , techniques like
Physical vapor deposition (PVD) ,Plasma assisted Ti-Si-N nanocomposite films chemical
Chemical Vapour deposition are used for nature was obtained by X-ray photoelectron
developing hard coatings on various substrates [6-8]. spectroscopy (XPS) using Multilab 2000. The
The aim of the present work is to study the structural confirmation was obtained by X-Ray
effect of substrate Power on structure of Ti-Si-N Diffraction studies carried out using Bruker X-ray
thin films .The chemical structural, topography and diffractometer by using Cu Kα radiation (λ=1.5406
resistivity parameters strongly dependent on the Ao). The topography and roughness of the films was
substrate power [9]. analysed atomic force microscope (Model:
A.P.E.Research A-100) and resistivity of films
2. EXPERIMENTAL DETAILS calculated from the four Probe method.
The 316L substrate surface was ground
with SiC paper to remove the oxides and other 3. RESULTS AND DISCUSSION
contamination. The polished substrates were 3.1. X-ray photoelectron spectroscopy analysis
degreased alkali solution containing sodium XPS survey spectra of the Ti-Si-N
hydroxide, followed by rinsing with triple distilled nanocomposite coatings shown in Fig.5.1a.The
water. These substrates were subsequently dipped in coatings exhibit the characteristic Ti2p, Si2p, N1s,
5 vol.-%H2SO4 solution for 1 min and thoroughly O1s and C1s peaks at the corresponding binding
rinsed in distilled water. energies 458.7, 101.5, 396.3, 531.7 and 283.8 eV
respectively. The high resolution spectra of Ti2p
showed (Fig.5.1b) the presence of oxide (TiO2) and
1839 | P a g e
2. Y.V.Subba Rao, B.S.Gangadhara, E.Suresh Babu, K.S.Sumana/ International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.1839-1842
nitride (TiN) phases in the surface at the (e)
corresponding binding energies 465.1 and 459.2 eV.
The binding energy of Si2p at 102.5 eV (Fig.5.1c)
corresponds to stoichiometric Si3N4. A peak on
396.4 eV shows the formation of TiN phase
(Fig.5.1d). The C 1s spectra of the films in Fig. 5.1e
show a typical characteristic of C-C bond with
binding energy around 284.9 eV [8,10]
(a)
Fig.3.1.Survey spectra of the Ti-Si-N coatings (a)
Survey, (b) Ti2p (c) Si2p (d) N1s (e) C1s.
3.2. X-Ray Diffraction
X-ray diffraction pattern of Ti-Si-N
nanocomposite coatings deposited onto glass
substrate at different powers is show in Fig.5.2.
The pattern shows only diffraction peaks
(b) due to crystalline TiN are observed, with no
indication of the presence of crystalline Si3N4
phases, suggesting that Si is present in amorphous
state at deposited power of 50 W. The observed d
values are in good agreement with the standard
values with JCPDS card no 087-0633 for TiN
coatings. XRD patterns revealed the presence of
only one phase that can be assigned to the cubic B1
NaCl structure, typical for TiN and the peaks
corresponding to (111), (200) and (220) planes were
observed.
(c)
Fig.3.2 XRD patterns for Ti-Si-N coatings
(a) 50 watt (b) 100 watt (c) 150 watt
(d) (d) 200 watt
The X-ray diffraction pattern of Ti–Si–N
films which shows only diffraction peaks with a
strongly TiN (2 0 0) preferred orientation at low
power. It is probably a solid solution (Ti, Si) N by a
substitution of Si for Ti in TiN lattice, because the
ionic radius of Si4+ ion (0.041nm) is smaller than
that of Ti3+ (0.075 nm) ion. The Ti–Si–N coatings
have somewhat mixed orientations (1 1 1), (2 2 0)
and (2 0 0). The intensity of the (2 0 0) peak
decreases with increasing in the content of power[8]
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3. Y.V.Subba Rao, B.S.Gangadhara, E.Suresh Babu, K.S.Sumana/ International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.1839-1842
Table 3.2 (a), (b), (c) and (d) shows calculation of (b)3D Image
the grain size, dislocation density, lattice parameter,
strain, texture coefficient and micro strain. The grain 3.4. Electrical studies
size can be calculated from XRD pattern, using the Electrical resistivity measurements of Ti-
formula. Si-N coatings on glass substrates were performed
0.9 using four-probe method at room temperature. In
this technique four probes are placed on a flat
Grain size: D = _________ surface of the substrates. Current is passed through
----- (5.1) the two outer electrodes and the floating potential is
cos measured across the inner pair. A nominal value of
probe spacing, which has been found satisfactory, is
Where, wave length of x – ray an equal distance of 1.5 nm between adjacent
(nm) probes. Resistivity can be calculated from the
Full width half maximum formulae
(mm) ρ = 4.532 x (V/I) x t -----------(Equation 3.4)
Position Where, V- measured voltage
I - current passed
Increasing the substrate power, grain size t – thickness of the coating
decreases whereas strain was found to increase. The
larger grain size of the film grown at 50 W is also an Resistivity (μohm-cm)
evidence of its high compaction (decreasing the Power 38°C 50°C 100°C 150°C
grain boundaries) confirmed by the highest intensity (watt)
of the diffraction peak for this temperature. 50 46.66 44.4 43.5 41.9
100 16.6 16.74 16.53 16.24
3.3. Morphological studies 150 9.5 9.59 9.73 9.73
The surface topography of the Ti-Si-N 200 47.2 47.0 46.2 45.4
coatings was studied using Atomic force
microscopy (AFM). The basic study comprised 2D
and 3D representations for a scanned area of 2X 2 Table.3.3. The electrical resistivity of the Ti-Si-N
m, which are shown in Fig 3.3. The roughness coatings for various substrate temperatures.
value, estimated from these images was 5.6 nm, Resistivity values of Ti-Si-N hard coatings in the
which shows that the films were very smooth in range of 9-47 μohm-cm are given in Table.3.3. It
nature[7] shows that these films have low electrical resistivity.
(a) When the power is increased the electrical resistivity
was found to decrease. While at a higher Si
concentration the resistivity increases (Fig.3.4).
(b) Fig.3.4 Resistivity measurements various
temperatures.
I. CONCLUSION
Ti-Si-N nanocomposite coatings were
prepared by reactive magnetron sputtering on to
different substrates at different power. The presence
of different phases like TiN, TiO2 and SiN were
confirmed by XPS analysis. From XRD analyses
results, Ti–Si–N nanocomposite coatings are mainly
composed of amorphous Si3N4 and TiN crystals
with a grain size of several nanometers. The Ti–Si–
N coatings have somewhat mixed orientations (1 1
Fig .3.3. AFM Images of Ti-Si-N (a)2D Image 1), (2 2 0) and (2 0 0). The intensity of the (2 0 0)
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4. Y.V.Subba Rao, B.S.Gangadhara, E.Suresh Babu, K.S.Sumana/ International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.1839-1842
peak decreases with increasing in the content of [6] J. Bonse, P. Rudolph, J. Kruger, S.
power. AFM analysis indicated that the coatings Baudach and W. Kautek, Ultrashort pulse
were regular with smooth structure . The Ti-Si-N laser ablation of polycarbonate and
shows low electrical resistivity coatings in the range polymethylmethacrylate Appl. Surf.
of 9-47 μohm-cm.. Sci.154/155, (2000), 659.
[7] Vipin chawla, RJayaganthan, and Ramesh
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