Effect of rare-earth Nd/Sm doping on the structural and multiferroic properties of BiFeO3 ceramics prepared by spark plasma sintering

Multiferroic Nd/Sm-doped BiFeO 3 ceramics synthesized at 700 °C by spark plasma sintering in conjunction with sol-gel precursor powders are investigated by X-ray diffraction, scanning electron microscopy, dielectric , ferroelectric and magnetic measurements. With the doping content of Nd/Sm beyond 10 mol%, the crystal structure changes from R 3 c to coexistence of Pbam and R 3 c . It is also revealed that the grain size for all samples greatly decreases and the dielectric, ferroelectric and magnetic properties are obviously improved with Nd/Sm doping. The optimized remanent polarization are about 1.451 μC/cm 2 and 3.448 μC/cm 2 for the 10 mol% Nd-doped and 15 mol% Sm-doped BiFeO 3 ceramics, respectively. Because of the reduced concentration of oxygen vacancies , the leakage current density of Nd/Sm-doped ceramics decreases more than two orders of magnitude compared to the pure BiFeO 3 sample. The maximum remanent magnetization for the Sm-doped ceramics is approximately 0.279 emu/g, which is higher than that for the Nd-doped samples (0.263 emu/g).