Deepika Tripathi

ABSTRACT We synthesized several polycrystalline samples with nominal composition BiFeO3 by single step solid state route. The synthesis parameters like sintering temperature, duration were varied and quenching sequence was used to stabilize single phase. The phase evolution was studied by using Powder X-Ray diffraction (XRD). We confirmed single phase nature and rhombohedral structure in the samples synthesized under optimized conditions. The characteristic low magnetic moment resulting from antiferromagnetic ordering was observed using SQUID magnetometer. We also studied microstructure behavior of these samples using Scanning Electron Microscopy technique.

ABSTRACT We report the synthesis of polycrystalline BiFeO3 compound by solid state route and its structural and magnetic properties were investigated. The structure confirmation and phase purity of the samples were investigated by X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. No signature of thermodynamically probable impurity phases was observed in these samples. The Rietveld refined structural parameters of the XRD pattern revealed rhombohedral (R3c) structure. Scanning Electron Microscopy images show samples with larger grain size. The Raman active modes predicted by the group theory confirmed the rhombohedral symmetry. The study of the oxidation states of Bi, Fe and O through XPS analysis indicated that the sample quality is not deteriorated by vacancies or other defects formation. The absence of iron based impurity phases is confirmed by the antiferromagnetic nature of the sample obtained by magnetization measurements.