无铅Bi_(0.5)(Na_(0.90-x)K_xLi_(0.10))_(0.5)TiO_3-NaNbO_3压电陶瓷的微结构与电学性能

Microstructure and Electrical Properties of Bi_(0.5)(Na_(0.90-x)K_xLi_(0.10))_(0.5)TiO_3-NaNbO_3 Lead-free Piezoelectric Ceramics

采用传统陶瓷工艺制备了Bi0.5(Na0.90-xKxLi0.10)0.5TiO3-NaNbO3无铅压电陶瓷,利用XRD、SEM等测试技术分析表征了陶瓷的结构、表面形貌、介电、压电与铁电性能.研究结果表明,该体系陶瓷具有单相钙钛矿结构,NaNbO3的引入使Bi0.5(Na0.90-xKxLi0.10)0.5TiO3体系的相界发生了移动;随着钾含量的增加,NaNbO3对体系性能的影响越明显.在室温下,该体系表现出较好的压电与铁电性能:压电常数d33和机电耦合系数kp分别达到174pC/N和29.6%,陶瓷样品表现出明显的铁电体特征,剩余极化强度达到33.4μC/cm2.

Lead-free piezoelectric ceramics, Bi0.5 （Na1-x-tKx Liy） 0.5TiO3 -NaNbO3 were fabricated by conventional electric ceramics processes, and the mierostructure, dielectric, piezoelectric and ferroelectric properties of the ceramics were investigated. X-ray diffraction patterns show that Bi0.5 （Na1-x-yKxLiy） 0.5 TiO3 -NaNbO3 can form a solid solution during sintering. With the addition of NaNbO3 , the dielectric, piezoelectric and ferroelectric properties of the ceramics strongly depend on the amount of K ^＋ . At room temperature, the ceramics exhibit good performances with piezoelectric constant d33 = 174 pC/N, eleetromeehanieal coupling factor kp = 29.6% , remnant polarization Pr = 33.4 μC/cm^2, and coercive field Ec = 2.7 kV/mm.