Synthesis and Characterization of Co-doped BiFeO3

Abstract

Multiferroic BiFeO3 and the cobalt doped BiFeO3 sample is prepared by sol – gel combustion technique using 2–methoxy ethanol and ethylene glycol as fuel. X-ray diffraction results confirm the formation of BiFeO3 as major phase with small amount of impurity phases, which are subsequently removed by leaching the sample with dilute nitric acid. The Rietveld refinement of all compositions shows there is a gradual decrease in lattice parameter with increase in cobalt concentration. DSC and TG plots of the samples shows there is a structural phase change from R3c to P3mm at 8290C and at higher temperatures appearance of impurity phases due to bismuth loss and liquid phases are seen. The SEM images of the sintered pellet show that the sample so prepared are having distribution of grain sizes which varies from 100nm - 1m. The grains shrink to smaller size, when the sample is doped with cobalt. EDXS of sample shows that the elemental composition is free from any foreign elements contamination. Dielectric measurement is done for all the samples from 100Hz to 1MHz. The low frequency dielectric constant of undoped sample is 36 and increases to 202 for 10% cobalt doped sample.
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