Switchable Ferroelectric Diode Effect and Piezoelectric Properties of Bi_0.9La_0.1FeO₃ Ceramics

Multiferroic ceramics Bi_0.9La_0.1FeO₃ are synthesized by solid−state reactions and sintered at various temperatures. The rhombohedral structure with the space group R3c is confirmed by means of x−ray diffraction, and their multiferroic properties are investigated. Bi_0.9La_0.1FeO₃ ceramics sintered at 880°C are found to have the lowest leakage current density and the largest saturated polarization among all the samples. A diode−like current-voltage hysteresis that could be switched by an external voltage is observed in the Bi_0.9La_0.1FeO₃ ceramics. A typical "butterfly" shaped strain−versus-voltage curve is shown with a maximum strain of 0.09% at 7 kV. Room-temperature magnetization exhibits a hysteresis loop, indicating that the modulation of the spin structure of BiFeO₃ has been suppressed.