Structural and Magnetic Properties of Bi0.5Sr0.5FeO3 Multiferroic Ceramics

Abstract

Phase pure BiFeO3 (BFO) and Bi0.5Sr0.5FeO3 (BFSO) ceramics were synthesized by solid state reaction method at different sintering conditions. Structural characterization with XRD revealed that the rhombohedral phase changed to cubic due to substitution of Sr in the A- site of BFO. SEM micrographs of BSFO samples indicated improved microstructure with higher density particularly the samples sintered for longer durations. The XPS data suggested the change in oxidation state of Fe from Fe3+ to Fe2+ as a result of aliovalent substitution of Sr at Bi site. As a consequence, oxygen vacancies were created to neutralize charge disorder. The BSFO samples exhibited ferromagnetism with enhanced remnant magnetization and coercive field as compared to the linear magnetization in BFO. These improved results obtained by Sr doping were majorly due to the structural change and creation of oxygen vacancies.