弛豫型铁电体PZNT制备与性能研究的进展

Progress in Studies on Fabrication and Properties of PZNT Relaxor Ferroelectrics

本文综述了近年来国际上弛豫型铁电体PZNT的制备与介电、压电及电致伸缩性能研究的进展．PZNT单晶体的制备方法以高温PbO熔剂法为主，其尺寸已达40mm．随PT含量的变化，PZNT的顺电一铁电相交由弥散性、混合型变为一级相变；其铁电-铁电相变可由组份或电场诱导，由介电性能表征．压电性能在MPB处及偏向三方相一侧达到最佳，＜001＞切向的三方相与四方相单晶可分别作为频带宽、分辨率高、且阻抗匹配好的新一代声阵列与单个器件传感器．＜001＞向的PZNT单晶具有巨大的电致伸缩应变，可望成为高性能的固体驱动器．

The present paper reviews the recent progress in studies on fabrication and dielectric piezoelectric and electrostrictive properties of relaxor ferroelectric PZNT. The dominant method offabrication of PZNT is the PbO flux method at high temperature, by which the single crystalswith size of 40mm have been grown. Studies on their dielectric properties indicated that thebehavior of phase transition of PZNT crystals would vary from diffused, mixed to first order transition type with the increase of PT concentration. The rhombohedral-tetragonal ferroelectric phasetransition is also diffused which can be induced by composition or electric field. Single crystalswith their composition at MPB or in the rhombohedral phase region near MPB have extremelystrong piezoelectric properties. The < 001 > oriented rhombohedral and tetragonal crystals arerespectively suitable for acoustic arrays and single element sensors and actuators with broaderbandwidth, improved sensitivity and optimum impedance matching. Crystallographically, highstrains are achieved for < 001 > oriented rhombohedral crystals and their levels reach an orderof magnitude of those available from conventional piezoelectric and electrostrictive ceramics suchas PZT series and PMNT ceramics, which make these crystals as promising candidates for highperformance solid actuators.