Structural evolution and its effect on multiferroic properties in magnetoelectric 0.67Sm0.12Bi0.88FeO3–0.33BaTiO3 ceramics by tuning the cooling rate

Abstract

The effects of cooling rate on structure and multiferroic properties were investigated in the lead-free 0.67Sm0.12Bi0.88FeO3–0.33BaTiO3 ceramics. Cooling in different medium induces the variations of phase fractions, c/a ratio and the distortion degree of oxygen octahedron, which can effectively regulate the multiferroic properties at room temperature. The high-temperature P4mm phase transforms to the Pm3m phase with the decrement of the cooling rate. The magnetoelectric coupling effect is nonlinearly related to the cooling rate, which is induced by the corresponding distortion in FeO6 octahedron. The ceramic cooled in water shows the largest remnant polarization of ~ 20.9 μC/cm2, while the ceramic cooled in furnace shows large remnant magnetization and magnetoelectric coupling coefficient of ~ 0.50 emu/g and 7.3 mV/(cm Oe), respectively.