Correlation of sintering temperature with structural and multiferroic properties of un-doped and cobalt doped bismuth ferrite

摘要

The crystal structure and physical properties of BiFeO3 and BiFe0.95Co0.05O3 sintered at various sintering temperature were studied using x-ray diffraction, scanning electron microscopy (SEM), electric and magnetic measurements. All the samples crystallize in a distorted perovskite structure with space group R3c and show minor impurity phase. An influence of various structural parameters and electronic states over physical properties of all the compounds were investigated. Partial covalency of the Bi-O bonds was confirmed using electron density calculation. Density functional theory (DFT) calculation has supported the validity of the experimental results. Moreover, microstructural investigation using the SEM shows that Co substitution in BiFeO3 increases the grain growth and increases the average grain size when sintered at 800 degrees C. P-E loop confirmed the ferroelectric behavior of synthesized compounds. The remnant magnetization Mr of BiFe0.95CO0.05 O-3 compound sintered at 850 degrees C was enhanced significantly, which provides potential applications of the material in information storage.