Dielectric, ferroelectric and piezoelectric properties of La-substituted BiFeO3–BaTiO3 ceramics

(Bi1−xLax)FeO3–BaTiO3 (BLxF–BT) polycrystalline ceramics were prepared by the mixed oxide route and the effect of La substitution on the microstructure and electrical properties of the ceramics was investigated. The main crystal structure of the ceramics is a perovskite structure with weak secondary phase. The addition of small amount of La2O3 was quite effective to improve the remanent polarization Pr and low coercive field Ec. Because of the relative lower Ec, larger Pr and good densification, the piezoelectric properties of the ceramics are evidently enhanced at x=0.02: d33=168 pC/N, kp=0.335. An obvious relaxor characteristics was observed with increasing La2O3 content.