IOSR-JAP   Volume-7 ~ Issue-1 ~ Jan-Feb 2015

ABSTRACT: One of the Electrical transport properties, Thermoelectric power of Co substituted Nickel Nano structured Ferrite materials with the formula Ni1-xCoxFe2O4, where (x=0.0,0.2,0.4,0.6,0.8 and 1.0) prepared by Citrate gel-auto combustion process were studied. The measurements were carried out from 320K to well beyondCurie temperature by the differential method. The Seebeck coefficient is negative for all compositions showing that these ferrites behave as n-type semiconductors. Plots of Seebeck coefficient verses temperature shows maximum at Curie temperature. On the basis of these results an explanation for the conduction mechanism in Ni-Co mixed ferrites is suggested .Compositional and temperature dependence of the Seebeck coefficient in the present ferrite system has been discussed. On the basis of these resultsa conduction mechanism for Ni-Co nano ferrites system is suggested in different temperature regions. The value of thermoelectric power shows maximum value at Tc (K).

Keywords: Ni-Co Nano Ferrites; Seebeck Coefficient; Conduction Mechanism;Curie Temperature

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ABSTRACT: The effects of pH of the reaction baths on the structural, optical and electrical properties of PbSe thin films have been investigated in the study. The thin films were deposited using the Chemical Bath Deposition technique and the samples were analyzed with X-Ray Diffraction (XRD) and UV-VIS-NIR spectrophotometry. The different sample thicknesses observed due to the variation of the deposition parameter are reported. The study revealed that the electrical conductivity and band gap energy of the samples decreases with thickness while the dielectric constant increased with thickness. This indicates that the solid state properties of the material can be controllably adjusted to achieve a desired function by variation of the deposition parameter in the deposition technique. Thus, by influencing the deposition of PbSe thin films through variation of it deposition parameters, it is possible to fabricate nanostructured materials with properties that can play significant roles in the production and utilization of thin films for solar system devices. Keywords: Band gap, Characterization, PbSe, pH, Solar devices, Thin film.

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ABSTRACT: A semi organic non linear optical material Bismuth sulpho chloride was synthesised by slow evaporatio9n technique. The modes of vibration of different molecular groups were identified using FTIR analysis. Surface morphology was estimated using SEM. Micro hardness studies were carried to crystal. Kurtz powder test was taken for grown crystals to study the non linear optical effect. A powder x-ray diffraction study shows the crystalline structure of grown Biscl crystals.

Keywords: X-ray diffraction, low temperature solution growth, NLO material.

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ABSTRACT: Chromium doped nanostructured tin oxide (Cr:SnO2) thin-films were prepared on glass substrates by the spray pyrolysis technique at constant substrate temperature of 450oC. The chromium dopant concentrations were taken as 10% and 20%, respectively. Structural, morphological and optical properties of the as-deposited thin films were studied. X-ray diffraction (XRD) analysis reveals the polycrystalline nature of Cr:SnO2 thin films with tetragonal phase. The films were highly oriented along (211), (002) and (400) planes. The increase in doping concentration impacts the interplaner spacing and crystallite size of the Cr:SnO2 thin films. Scanning electron microscope (SEM) images support the XRD analysis of the thin films, while the optical absorbance study suggests blue-shift in the energy band gap with increase in the doping concentration. Keywords: Cr: SnO2 thin-film, nanocrystalline thin film, spray pyrolysis, X-ray diffraction, optical properties.

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