P. Prabukanthan; R. Lakshmi; T. Rajesh Kumar; S. Thamaraiselvi; G. Harichandran
Abstract
Electrochemical deposition (ECD) of FeS2 thin films from aqueous solution contains FeSO4, Na2S2O3.5H2O and H2SO4. ECDs were performed at different bath temperatures (30, 40, 50, 60 and 70°C) with constant pH (~2). FESEM images shows that the grains are as deposited films with stoichiometric ...
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Electrochemical deposition (ECD) of FeS2 thin films from aqueous solution contains FeSO4, Na2S2O3.5H2O and H2SO4. ECDs were performed at different bath temperatures (30, 40, 50, 60 and 70°C) with constant pH (~2). FESEM images shows that the grains are as deposited films with stoichiometric iron pyrite thin films were successfully formed at 50, 60 and 70°C and S/Fe ratio in as-deposited films were ~2. GAXRD studies of as-deposited at 30 and 40°C FeS2 thin films shows a minor phase of orthorhombic marcasite and major cubic pyrite phase observed. As-deposited thin films at 50, 60 and 70°C brings about the formation of FeS2 with single crystalline cubic phases with a strong (111) preferred orientation and without any contribution of marcasite phase. When the bath temperature was increased, as-deposited thin films of crystalline size, thickness and roughness value increased due to rate of formation FeS2 increased. Raman spectra of the FeS2 thin films presented characteristic peaks of S-S active mode at 377 cm-1. The optical spectra of the as-deposited FeS2 thin films with different bath temperatures showed a clear absorption edge band gap of these films from 0.86 to 0.96 eV. As-deposited FeS2 thin films at different bath temperatures show p-type conductivity. Copyright © 2017 VBRI Press.
M. Malligavathy; D. Pathinettam Padiyan
Abstract
Phase pure bismite nanoparticles were successfully prepared by means of hydrothermal method by varying the precursor solution pH from 10 to 13. The as-prepared nanoparticles were characterized by different techniques such as X-ray diffraction pattern (XRD), Raman spectroscopy, Scanning electron microscopy ...
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Phase pure bismite nanoparticles were successfully prepared by means of hydrothermal method by varying the precursor solution pH from 10 to 13. The as-prepared nanoparticles were characterized by different techniques such as X-ray diffraction pattern (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX). The effects of pH on the structural properties of these nanoparticles were corroborated using XRD and Raman spectrum. From the XRD pattern it is found that all the samples are polycrystalline in nature and the Raman spectra are used to confirm the phase transformation of the Bi2O3 nanoparticles. At the low pH value, the SEM image reveals that as-prepared samples are homogeneous with particle size of ~ 25 nm and with the increase in the pH value spherical particle forms uniform blocks like morphology for both the samples prepared at the pH 12 and 13. Copyright © 2017 VBRI Press.
