The Multiferroic Properties of BiFeO 3 –Na 0.5 Bi 0.5 TiO 3 Solid Solution Ceramics

Solid solutions of 80% BiFeO 3 and 20% Na 0.5 Bi 0.5 TiO 3 (BFO-NBT), and 80% Bi 0.95 La 0.05 FeO 3 and 20% NBT (BLFO-NBT) were prepared by the conventional sol–gel method. Clear ferromagnetic hysteresis loops were observed for both samples. The poling electric field strongly suppressed the magnetization of BFO-NBT, while showing negligible influence on that of BLFO-NBT. The reorientation of magnetization by the poling field has been excluded. The strongly suppressed magnetization in poled BFO-NBT was attributed to the decreased concentration of defect configurations due to the redistribution of oxygen vacancies under electric field, which was weakened by 5% La substitution.