多铁性陶瓷BiFeO_3-PbTiO_3-BaTiO_3的介电、压电及其老化性能研究

采用高温固相法制备了钙钛矿结构的0.7BiFeO_3-0.2PbTiO_3-0.1BaTiO_3陶瓷,研究了该陶瓷的介电性能、压电性能及其老化性能。结果表明,该陶瓷是一种非常有潜力的高温压电陶瓷,其介电常数和介电损耗分别为390和0.015,铁电居里温度TC约为600℃,压电常数d_(33)约为100 pC/N,压电常数的时间稳定性和热稳定性好,热退极化温度Td约为500℃。压电常数热退极化机理主要为内在的剩余极化老化,辅以低浓度氧空位等外在缺陷对畴壁的钉扎作用。

Dielectric, Piezoelectric and Aging Properties of Multiferroic Ceramics BiFeO3-BaTiO3-PbTiO3

Multiferroic ceramics 0.7BiFeO3-0.2PbTiO3-0.1BaTiO3 (abbreviated as BF-BT-PT) was prepared by high temperature solid state method. The dielectric, piezoelectric properties and the aging behaviors were investigated. The results suggested that BF-PT-BT ceramics was a high potential lead-reduced high-temperature piezoceramics with excellent properties including the dielectric constant =390, =0.015, the piezoelectric coefficient of d33 ~100pC/N, the Curie temperature of Tc~600oC, good stability with the thermal depoling temperature of Td ~500oC. The primary thermal depoling mechanism was the decrease of remnant polarization, associated with the pinching effect on domain walls of low density oxygen vacancy defects.