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Non-stoichiometric nickel oxide was synthesized by solid state route method at different sintering temperatures upto 1100 °C. The structure of synthesized compounds were analyzed by X ray diffraction analysis (XRD) and the dielectric constant was found to different for samples of different stoichiometry. These results were interpreted as the decomposition temperature increases, which heals the defects present in the non-stoichiometric nickel oxide and loss peak shifts to the higher frequency which is due to long range hopping of charge carriers. [ABSTRACT FROM AUTHOR]

The density of state of material is depending on the size of materials. The electronic properties of the material can be tailored by proper selection of synthesis process. Further, microstructure of anode materials for solar cell like ZnO, Al2O3, TiO2 etc., plays crucial role in the effective absorption of sun light. In the present work, TiO2 based powder with anatase phase has been synthesized by hydrothermal method with NaOH in a vacuum oven at 150 °C and annealed at 500 °C for 4 hours. The X-ray diffraction data reveals that synthesized TiO2 powder exhibit tetragonal crystalline structure with space group I41/amd (#141). The transmission electron microscopy shows the formation of TiO2 nano rods with almost uniform thickness in range 7-10 nm. This fact is also confirmed with similar formation of rods in scanning electron microscopy. The better absorption is observed in the sample as revealed by UV-Visible spectroscopy and the band gap is obtained from Tauc's relation is ~ 3.25 eV. [ABSTRACT FROM AUTHOR]

The bulk Sm doped BaTiO3 ceramics have been prepared using solid state reaction method. The prepared bulk ceramics have been characterized using x-ray diffraction and dielectric measurements. X-ray diffraction results show the single-phase nature of Sm doped BaTiO3 ceramics. Dielectric properties of the Sm doped BaTiO3 ceramics have been measured as a function of frequency room temperatures. It is observed that dielectric constant increases initially with Sm doping, and then start decreasing with further increasing in Sm doping. Dielectric constant of all the samples show dispersion behavior. It is observed that at lower value of frequency the dielectric constant decreases rapidly and becomes frequency independent at higher value of the frequency. It is found that the dielectric loss decreases with frequency for app the composition, however for pure and 3% Sm doped BaTiO3, dielectric loss increases initially up to 500 kHz and then decrease with further increases in frequency and becomes independent at higher frequency. [ABSTRACT FROM AUTHOR]

Zn doped NiO samples have been synthesized by solid state reaction method, using Nickel oxide and Zinc Oxide as a precursors, at 1000 ͦC. The structure of synthesized compounds was analyzed by X ray diffraction analysis (XRD) and FTIR spectroscopy studies were employed to understand the influence of doping Zn on the structural and spectroscopic properties of the NiO compound. The results revealed that Zn doping has significant influence on crystallinity and particle size of the nickel oxide. The NiO bands were also shifted towards lower frequency region because of Zn doping. [ABSTRACT FROM AUTHOR]

Polycrystalline Ba(Dy1/2Nb1/2)O3 was prepared using a high-temperature solid-state reaction method. X-ray diffraction analysis indicated the formation of a single-phase cubic structure having space group Pm3m. AC impedance plots as a function of frequency at different temperatures were used to analyse the electrical behaviour of the sample, which indicated the negative temperature coefficient of resistance character. Complex impedance analysis targeted non- Debye type dielectric relaxation. Frequency dependent ac conductivity data obeyed Jonscher's power law. The apparent activation energy was estimated to be 0.97 eV at 1 kHz. [ABSTRACT FROM AUTHOR]

Mn thin film deposited GaAs samples were implanted with 250 keV Ar+2 ions for various fluences 5×1015, 1×1016 and 5×1016 ions cm-2. Optical and structural properties of the samples have been investigated by using ultraviolet spectroscopy and X-ray diffraction techniques. Optical absorbance of the implanted samples was found to decrease with increase in argon ion fluence. XRD spectra of the samples implanted for ion fluences 5×1015 and 1×1016 showed the formation of (GaMn)As at 2[phonetic_theta] value of 65.34 deg. The XRD spectrum of sample 1×1016 cm-2 annealed at 450° C showed the formation of magnetic phases. [ABSTRACT FROM AUTHOR]

In the present work, 325 keV Mn+ ions were implanted into semi-insulating GaAs substrate with various fluences varying from 1×1015 to 1×1016 ions cm-2. Post annealing was carried out using 5 MeV Si+ ions irradiation at substrate temperature of 350 °C to remove the Mn+ implantation damage. The properties of as implanted and post annealed samples were measured using superconducting quantum interference device (SQUID), X-ray diffraction and Raman scattering to characterize the structural changes. Zero-field-cooled (ZFC) and field-cooled (FC) magnetization as function of temperature were recorded for sample irradiated with 5 MeV silicon ions. X-ray diffraction study revealed the presence of magnetic phase of (GaMn)As. The sharpness of LO mode peak, after irradiation with silicon ions indicated the crystilinity of the sample. The Mn-like mode and (MnAs) like mode were also observed. [ABSTRACT FROM AUTHOR]

Synthesis of Silver Sulfide nanoparticles of various morphologies were successfully done through colloidal synthesis technique at relatively low temperature using Chitosan bio polymer as stabilizer. The effect of change in stabilizer concentration, reagent concentrations and reaction temperature at constant pH on morphology and optical properties of synthesized products are also studied. It was found that reagent concentration and temperature both played important role in change in morphology of synthesized product. The crystal structure studies of synthesized products were carried out by powder X-ray diffraction technique which reveals the formation of Acanthite monoclinic Ag2S crystal structure and SAD was taken for only two samples whose analysis using XRD was difficult. The optical properties and quantum confinement effect of the products were confirmed by means of spectroscopic measurements. Morphologies obtained were characterized by SEM. Further the functionality and effectiveness of stabilization process were established by Fourier transform infrared spectroscopy. [ABSTRACT FROM AUTHOR]

Thermal decomposition method was used to synthesize non-stoichiometric nickel oxide at different sintering temperatures upto 1100 °C. The structure of synthesized compounds were analyzed by X ray diffraction analysis (XRD) and magnetic ordering was studied with the help of Raman scattering spectroscopy for the samples sintered at different temperature. It was found that due to change in sintering temperature the stoichiometry of the sample changes and hence intensity of two magnon band changes. These results were interpreted as the decomposition temperature increases, which heals the defects present in the non-stoichiometric nickel oxide and antiferromagnetic spin correlation changes accordingly. [ABSTRACT FROM AUTHOR]

Cd1-xZnxTe (where x = 0.02, 0.04, 0.06, 0.08) thin film have been deposited on glass substrate at room temperature by thermal evaporation technique in a vacuum at 2×10 -5 torr. The structural analysis of the films have been investigated using X-ray diffraction technique. In low temperature range the thermal activation energy corresponding to the grain boundary- limited conduction is found to be in the range of 38 μeV to 48 μeV, but in the high temperature range the activation energy varies between 0.86 meV to 1.01 meV. [ABSTRACT FROM AUTHOR]