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Swift heavy ion irradiation is performed on 5% Ag doped Ge2Sb2Te5 (GST) thin films to observe the changes in structural and optical properties. The thin films have been irradiated with Ag9+ ions having 120 MeV energy. It has been observed that irradiation does not leads to phase change and the red shift observed in Raman spectra indicates the weakening of bond strength. Moreover, reduction in bandgap is also observed as an effect of increasing irradiation dose. These results indicate that the irradiation with high energy ions introduces defects in the thin films which may lead to local generation of crystal nuclei. These crystal nuclei may be responsible for the modification of optical and electrical properties in these films. [ABSTRACT FROM AUTHOR]

Thin films of pure and 3% Al-doped nano-crystalline SnO2 were deposited by spin coating method on glass substrates. Structural, morphological and electrical properties of the deposited films were investigated. X-ray diffraction results confirmed the formation of tetragonal phase in the deposited films. Fourier transform infrared spectroscopy results confirmed the presence of Sn-O-Sn, and Sn-O bonding in the deposited films. Addition of Al to SnO2, leads to shift in vibrational modes due to smaller radius of dopant moiety. Field emission scanning electron microscopy results depicted that with Al-doping the average particle size reduced as compared to pure sample. An increase in electrical current was observed with addition of dopant material than pure sample. [ABSTRACT FROM AUTHOR]

In this work thin films of the phase change material Ge2Sb2Te5 (GST), pure and Ag-doped, were studied. These films were prepared by thermal evaporation method. Amorphous nature of both pure and Ag-doped GST thin films has been confirmed from X-ray diffraction analysis. Raman spectra confirms the host structure of GST which is confirmed by the two sharp peaks at 126.4 cm-1 and 144.9 cm-1 for GST thin films. The hole concentration was found to increase by three orders of magnitude due to Ag doping, as measured by Hall measurements. I-V measurements of the samples show thermal switching at moderate voltage as large current flows through Ag-doped GST. The increase in conductivity was attributed to the crystallization of the films due to heating caused by the large electric current for I-V measurements. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiO), a potential candidate for optoelectronic is so sensitive that small amount of impurities changes its properties extensively. Here, nanostructured NiO has been synthesized by co-precipitation method. The effect of Fe (3%, 5%, 7%, 10% and 15%) doping on structural, morphological and optical properties of NiO nanostructures has been studied. XRD analysis confirms the formation of face centered cubic with preferential grown along (220) plane. Nelson riley factor analysis revealed the presence of defect states in the synthesized nanostructures. Photoluminescence spectroscopy results revealed that the variation of defect states with dopant content leads to the variation in the photoluminescence properties of the synthesized samples. [ABSTRACT FROM AUTHOR]

In the present study, pure Magnesium oxide (MgO) nanoparticles have been synthesized by solid combustion method. Effect of annealing on the structural properties of the MgO nanoparticles has been analyzed. X-ray diffraction (XRD) patterns show the formation of cubic phase of MgO in both as-prepared and annealed (850 °C) samples. Crystallite size of the as-prepared and annealed samples estimated by Scherrer formula is ~15 nm and ~18 nm respectively, which is validated by Williamson-Hall plot method. Rietveld refinement analysis of XRD patterns has been carried out to calculate various crystallographic parameters and to investigate defects in lattice. Presence of Mg vacancies is inferred from refinement. Texture coefficient of the crystal planes is calculated to inspect preferred growth direction of crystals. [ABSTRACT FROM AUTHOR]

In present work, we report synthesis, X−ray diffraction study and photoluminescence of SrZnO2. The SrZnO2 phosphors were prepared through high energy ball milling process and subsequent annealing. The annealing at various temperatures helped in emergence of single phased SrZnO2 phosphors. The texture coefficient of prominent planes was found to be growing with annealing temperature. At an excitation wavelength of 325 nm, the photoluminescence spectrum is spanning from yellow to IR region. As SrZnO2 is wide band gap phosphor, so the observed emission is believed to be due to oxygen vacancies or cation interstitial defects. [ABSTRACT FROM AUTHOR]

Nanostructured NiO has been prepared by co-precipitation method. In this study, the effect of fluorine doping (1, 3 and 5 wt. %) on the structural, morphological as well as optical properties of NiO nanostructures has been studied. X-ray diffraction (XRD) has employed for studying the structural properties. Cubic crystal structure of NiO was confirmed by the XRD analysis. Crystallite size increased with increase in doping concentration. Nelson-Riley factor (NRF) analysis indicated the presence of defect states in the synthesized samples. Field emission scanning electron microscopy showed the spherical morphology of the synthesized samples and also revealed that the particle size varied with dopant content. The optical properties were studied using UV-Visible Spectroscopy. The results indicated that the band gap energy of the synthesized nanostructures decreased with increase in doping concentration upto 3% but increased as the doping concentration was further raised to 5%. This can be ascribed to the defect states variations in the synthesized samples. The results suggested that the synthesized nanostructures are promising candidate for optoelectronic as well as gas sensing applications. [ABSTRACT FROM AUTHOR]

This work focus on high surface area morphology of manganese oxide films which are currently required for electrochemical capacitor electrode to enhance their performance. Electrodeposition of manganese oxide films was carried out using Chronoamperometry for different deposition time ranging from 30 to 120 sec. Cronoamperomertic I-T integrated data have been used to analyze active mass of all electrodeposited films. Morphological study of the deposited films with different mass was carried out through scanning electron microscopy. Film deposited for 30 sec time show highest porous morphology than others. Manganese oxide films with high porosity are suitable for electrochemical capacitor electrode. [ABSTRACT FROM AUTHOR]

The synthesis of marcasite FeS2 is of great interest as this area is seldom studied due to its sophisticated synthesis methods. In fulfillment of growing energy demands, there is need of cost effective alternates for energy storage devices. Nanostructured marcasite iron disulfide (FeS2) is a promising candidate as anode material for energy storage devices. FeS2 exist in many phases out of which marcasite and pyrite are best suitable for energy storage applications. Purity of the phase is a big challenge for its application oriented use. Pure marcasite (FeS2) has been synthesized by low cost, environmentally friendly hydrothermal route. The synthesized material has been characterized by X-ray Diffraction (XRD). Cyclic voltammetry results show the significant electrochemical performance of marcasite. This work purposes a vision to develop marcasite based electrode material for energy storage devices. [ABSTRACT FROM AUTHOR]

Nanocrystalline ZnxTe100-x (x=0, 5, 20, 30, 40, 50) alloys have been synthesized using melt quenching technique. Energy-dispersive X-Ray spectroscopy (EDS) has been used to verify the elemental composition of samples. Various absorption modes are recorded from Fourier transform infrared spectroscopy (FTIR) confirming the formation of ZnTe. The structural study has been performed using X-Ray Diffraction (XRD) method. All synthesized samples have been found to be nanocrystalline in nature with average crystallite size in the range from 49.3 nm to 77.1 nm. Results have shown that Zn0Te100 exhibits hexagonal phase that transforms into a cubic ZnTe phase as the amount of zinc is increased. Pure ZnTe phase has been obtained for x = 50. The texture coefficient (Tc) has been calculated to find the prominent orientations of different planes. [ABSTRACT FROM AUTHOR]

Zinc aluminate (ZnAl2O4) has proved to be a potential candidate in many areas such as catalysis, display panels, pigments in paints, radiation dosimetry, luminescence etc. Here, we report the solution combustion synthesis & spectroscopic studies of ZnAl2O4 nanoparticles. Urea (fuel) and metal nitrates (oxidizer) were taken in stoichiometric ratio at 1:1. The X-ray diffraction analysis of the as-prepared and annealed samples showed all reflection planes pertaining to ZnAl2O4. However, a weak intensity peak of secondary phase was also observed at 2θ value of 34.5°, which correspond to the diffraction plane (002) of ZnO. This phase was found to disappear after annealing the sample at 1000 °C for 1 hour. Fourier transform infrared spectroscopy (FTIR) also inferred the formation of ZnAl2O4. Photoluminescence measurements carried out on samples at excitation wavelength of 345 nm showed that ZnAl2O4 is an efficient luminescent material with emission in violet region of visible spectra. [ABSTRACT FROM AUTHOR]

Boron- carbon core shell structures have been synthesized by solvo-thermal synthesis route. The synthesized material is highly pure. X-ray diffraction analysis confirms the reduction of reactants in to boron and carbon. Scanning Electron Microscopy (SEM) analysis showed that the shell is uniform with average thickness of 340 nm. Photo luminescence studies showed that the material is blue light emitting with CIE color coordinates: x=0.16085, y=0.07554. [ABSTRACT FROM AUTHOR]

Multilayer nanowires were fabricated by potentiostate ectrodeposition template synthesis method into the pores of polycarbonate membrane. In present work layer by layer deposition of two different metals Ni and Cu in polycarbonate membrane having pore size of 600 nm were carried out. It is found that the growth of nanowires is not constant, it varies with deposition time. Scanning electron microscopy (SEM) is used to study the morphology of fabricated multilayer nanowires. An energy dispersive X-ray spectroscopy (EDS) results confirm the composition of multilayer nanowires. The result shows that multilayer nanowires formed is dense. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) nanoparticles have been synthesized by co-precipitation method. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) and Raman spectroscopy. XRD analysis confirmed the single phase formation of SnO2 nanoparticles. The Raman shifts showed the typical feature of the tetragonal phase of the as-synthesized SnO2 nanoparticles. At low annealing temperature, a strong distortion of the crystalline structure and high degree of agglomeration was observed. It is concluded that the crystallinity of SnO2 nanoparticles improves with the increase in annealing temperature. [ABSTRACT FROM AUTHOR]

Amorphous selenium (a-Se) and a-Se95Sb5 alloy were prepared using melt quenching technique. X-ray diffraction (XRD) pattern confirmed the amorphous nature of the prepared samples. Composition of the prepared samples has been determined using Energy dispersive X-ray fluorescence (EDXRF) technique. Differential thermal analysis (DTA) confirmed the glassy nature of the prepared samples. Thin films of the prepared samples were deposited on glass substrate using thermal evaporation method. Amorphous nature of the deposited films was confirmed using XRD. Optical properties of these films were obtained from the UV-VIS transmission spectra, at normal incidence, over 200-1100 nm spectral range. The optical absorption edge was described by using the model given by the Tauc. Optical band gap of the deposited films was calculated using Tauc plot. Optical characterization showed that average transmission and optical band gap decreased with the addition of antinomy. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) thin films were deposited by radio-frequency (RF) magnetron sputtering on silicon and glass substrates in different oxygen-to-argon gas-flow ratio (O2-to-Ar = 0%, 10%, 50%). All films were deposited at room temperature and fixed working pressures, 10 mTorr. The X-ray diffraction (XRD) measurement suggests that all films were crystalline in nature except film deposited in argon environment. Thin films were annealed in air at 200 °C, 400 °C and 600 °C for two hours. All films were highly transparent except the film deposited only in the argon environment. It was also observed that transparency was improved with annealing due to decrease in oxygen vacancies. Atomic force microscopy (AFM), results showed that the surface of all the films were highly flat and smooth. Blue shift was observed in the absorption edge with annealing temperature. It was also observed that there was not big change in the absorption edge with annealing for films deposited in 10% and 50% oxygen-to-argon gas-flow ratio. [ABSTRACT FROM AUTHOR]

Copper nanowires were fabricated within the pores of anodic alumina template (AAT) by template synthesis method at pH = 2.9. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to investigate the structure, morphology and composition of fabricated nanowires. These characterizations revealed that the deposited copper nanowires were highly crystalline in nature, dense and uniform. The crystalline copper nanowires are promising in application of future nanoelectronic devices and circuits. [ABSTRACT FROM AUTHOR]

(Ge2Sb2Te5)90Ag10 (GST-Ag) bulk alloy was prepared using melt quenching technique. GST-Ag thin film was deposited on glass substrate using thermal evaporation method. The prepared thin films were exposed to visible light (intensity of 105 Lux for 2, 8, 20 and 30 hours) using 25W LED lamp. Transmission spectra were taken using UV-vis-NIR spectrophotometer in the wavelength range 800-3200 nm. Optical band gap of as-deposited and light exposed thin films was determined using Tauc’s plot. Optical band gap was found to be decreasing on light exposure upto 8 hours and after that no significant change was observed. [ABSTRACT FROM AUTHOR]

Nanostructured Boron Nitride (BN) has been successfully synthesized by carbo-thermic reduction of Boric Acid (H3BO3). This method is a relatively low temperature synthesis route and it can be used for large scale production of nanostructured BN. The synthesized nanoparticles have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analyzer (DTA). XRD analysis confirmed the formation of single phase nanostructured Boron Nitride. SEM analysis showed that the particles are spherical in shape. DTA analysis showed that the phase is stable upto 900 °C and the material can be used for high temperature applications as well boron neutron capture therapy (BNCT). [ABSTRACT FROM AUTHOR]

Nitrogen doped SnO2thin films (thickness ~ 250 nm) were deposited at different substrate temperature by radio frequency (rf) sputtering method. Crystal structure, morphology and optical properties of these films were investigated by x-ray diffraction (XRD), atomic force microscopy (AFM) and UV-VIS-NIR spectrophotometer, respectively. XRD measurement suggests that the film deposited at room temperature was amorphous in nature and films deposited at higher temperature were crystalline in nature. The film deposited at RT and 200 °C have transparency more than 90% in visible region but the film deposited at 400 °C has lesser transparency. Red shift was observed in the absorption edge may be due to decrease in ionicity due tothe formation of the Sn-N bond. [ABSTRACT FROM AUTHOR]

ZnO thin films (thickness ∼ 400 nm) were prepared at different oxygen content (O2) by radio frequency (rf) sputtering method. Crystal structure and optical properties of these films were investigated by x-ray diffraction (XRD) and UV-VIS-NIR spectrophotometer, respectively. XRD measurement suggests that all films have hexagonal wurtzite structure. The transparency in the visible region of all the film is more than 90%. The optical absorption edge was described using the direct transition model proposed by Tauc and the optical band gap was calculated from the absorption coefficient by Tauc's extrapolation procedure. The value of optical band gap was decreased with increase in the O2 content; due to Burstein-Moss shift. [ABSTRACT FROM AUTHOR]

The effect of Ne+ ion sputtering on amorphous Ga-In-Zn-O (a-GIZO) thin films was investigated by using surface-sensitive, synchrotron-radiation-based, high-resolution X-ray photoelectron spectroscopy (XPS). a-GIZO thin films having different compositions (Ga2O3:In2O3:ZnO = 1:1:1, 2:2:1, 3:2:1, 4:2:1) were investigated. It was found out that the amounts of the In and Zn contents relative to that of Ga decreased noticeably after sufficient sputtering, and that there occurred a subgap state above the valence band maximum and metallic states at the In 3d and 4d core levels as well as at the Fermi edge. [ABSTRACT FROM AUTHOR]

Transparent oxide semiconductor, a-GaInZnO, thin films were deposited by radio frequency (RF) magnetron sputtering at different oxygen/Argon (O2/Ar) flow ratio on glass substrates. The effect of oxygen content was studied on the transmittance and optical band gap of these thin films. The average transmittance in the visible region decreased with increase in the oxygen content. The optical band gap also decreased with increase in the oxygen content. With increasing oxygen content, the absorption edge shifted to the longer wavelength due to the decreased Burstein-Moss effect. [ABSTRACT FROM AUTHOR]

In present work, we report synthesis, X−ray diffraction study and photoluminescence of SrZnO2. The SrZnO2 phosphors were prepared through high energy ball milling process and subsequent annealing. The annealing at various temperatures helped in emergence of single phased SrZnO2 phosphors. The texture coefficient of prominent planes was found to be growing with annealing temperature. At an excitation wavelength of 325 nm, the photoluminescence spectrum is spanning from yellow to IR region. As SrZnO2 is wide band gap phosphor, so the observed emission is believed to be due to oxygen vacancies or cation interstitial defects. [ABSTRACT FROM AUTHOR]