Enhanced piezoelectric and ferroelectric properties of BiFeO3-BaTiO3 leadfree ceramics by optimizing the sintering temperature and dwell time

摘要

0.7BiFeO(3)-0.3BaTiO(3) (BFO-O.3BT) ceramics were prepared to uncover the impacts of sintering temperature (T-s) and dwell time (t(d)) on the microstructure and electrical properties. With increasing the T-s or t(d), the grain sizes increase along with the porosity decreases, which is in favor of the alignment of dipole. However, excess T-s or t(d) are inclined to cause the volatilization of Bi2O3, which deteriorates piezoelectric properties. Because of the R-T two phase coexistence, low defect ions concentration and porosity, as well as appropriate grain size, the excellent d(33) = 208 pC/N and k(p) = 35.46% as well as P-r = 28.52 mu C/cm(2) were achieved in BFO-0.3BT ceramics at T-s = 1000 degrees C and t(d) = 6 h. In addition,large unipolar strain 0.13% and d(33)* = 256.2 pm/V also were obtained in BFO-0.3BT ceramics at T-s = 1000 degrees C and t(d) = 6h. This research indicates that the porosity and defect ion concentration as well as grain size also play an important role in piezoelectric properties in BFO-BT ceramics.