Effect of transition metal element substitution on magnetoelectric properties of BiFeO3-BaTiO3 ceramics

Abstract

BiFeO3 is the most typical multiferroic materials. However, the poor magnetoelectric coupling effect limits its practical application. In this work, the transition metal elements (Co, Mn) were introduced to suppress the spin cycloid structure of BiFeO3-based ceramics. The structure, ferroelectric, magnetic and magnetoelectric properties were investigated thoroughly. The XRD and SAED analysis confirmed the coexistence of tetragonal (T) and rhombohedral (R) phases of all samples. The piezoelectric properties were enhanced in Co-substituted samples. In addition, the magnetic properties were enhanced with the addition of Co/Mn ions. According to the analysis of the M-H loops and XRD patterns before and after poling, the electric-field induced magnetic change was observed in all samples, which can be attributed to the phase transition from R-phase to T-phase during poling. The room-temperature linear magnetoelectric coefficient αME was analyzed, and the maximum αME was obtained at BF-BT-005BC sample, where αME = 0.66 mV/cm Oe. The enhanced magnetic and magnetoelectric properties were ascribed to the distortion of the spiral spin structure by transition metal ions.