Enhanced magnetoelectric coupling characteristics of Mn2O3-modified BiFeO3-based ceramics

Abstract BiFeO3 is the most important room-temperature multiferroic material. However, the magnetoelectric coupling effect of BiFeO3 is weak, and an effective way to improve it is to suppress the spin cycloid structure. In this work, Mn ions were substituted into BiFeO3-based ceramics to enhance the magnetoelectric coupling effect. All samples were refined with the rhombohedral R3c structure. The grain size gradually decreased with increasing Mn substitution content. According to DSC analysis, the endothermic peak and exothermic peak exhibit an obvious thermal hysteresis behavior, indicating that it is the first-order ferroelectric transition. Meanwhile, a dielectric anomaly was also found at that transition temperature. The leakage current increased with increasing Mn content, which can be ascribed to the increased oxygen vacancies. The magnetic properties were enhanced for all samples, and the maximum Mr = 51.9 emu/mol was obtained for x=0.03 Mn. In addition, the magnetoelectric properties were improved, and the value of linear magnetoelectric coefficient exhibits a maximum value αME=0.38 mV/cm Oe at x=0.03. Thus, the addition of Mn at Fe sites may destroy the spin cycloid structure and enhance the ME effect of BiFeO3.