Lead-free piezoelectric ceramics: Alternatives for PZT?
Lead-free piezoelectric ceramics: Alternatives for PZT?
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DOI：
10.1007/s10832-007-9095-5
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发表时间：
2007
影响因子：
1.7
通讯作者：
T. Shrout;Shujun Zhang
中科院分区：
文献类型：
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作者：
T. Shrout;Shujun Zhang
近年来，对无铅压电陶瓷的研究表明，其性能可与以PZT为代表的铅基铁电钙钛矿材料相媲美。在这项工作中，将这些材料的科学和技术影响与各种“软”和“硬”类PZT进行了对比。在科学前沿，介电和压电性能的本征性质与它们各自的居里温度(TC)和准同型相界(MPB)的存在有关。与PZT类似，在(Na，Bi)TiO_3-BaTiO_3和(K，Bi)TiO_3三元体系中，MPB组分的性能得到了提高，但性能显著降低。铁电到反铁电转变的后果远低于Tc，进一步限制了它们的用途。虽然与TOTC相比，(K，Na)NbO_3系列中所报道的高水平的压电性是由于与正交-四方多形相变的成分向下移动而增强的极化率的结果。正如预期的那样，这些性质强烈地依赖于温度，而退化是通过两个不同的铁电域态之间的热循环发生的。利用高场应变和极化测量确定了来自磁区和磁区壁迁移率的非本征贡献。讨论了“软”和“硬”无铅压电材料的概念，分别与施主和受主修饰的PZT相联系。在技术上，讨论了无铅材料的一般应用，包括传感器、致动器和超声波换能器。
Investigations in the development of lead-free piezoelectric ceramics have recently claimed comparable properties to the lead-based ferroelectric perovskites, represented by Pb(Zr,Ti)O3, or PZT. In this work, the scientific and technical impact of these materials is contrasted with the various families of “soft” and “hard” PZTs. On the scientific front, the intrinsic nature of the dielectric and piezoelectric properties are presented in relation to their respective Curie temperatures (TC) and the existence of a morphotropic phase boundary (MPB). Analogous to PZT, enhanced properties are noted for MPB compositions in the (Na,Bi)TiO3-BaTiO3and ternary system with (K,Bi)TiO3, but offer properties significantly lower. The consequences of a ferroelectric to antiferroelectric transition well belowTCfurther limits their usefulness. Though comparable with respect toTC, the high levels of piezoelectricity reported in the (K,Na)NbO3family are the result of enhanced polarizability associated with the orthorhombic-tetragonal polymorphic phase transition being compositionally shifted downward. As expected, the properties are strongly temperature dependent, while degradation occurs through the thermal cycling between the two distinct ferroelectric domain states. Extrinsic contributions arising from domains and domain wall mobility were determined using high field strain and polarization measurements. The concept of “soft” and “hard” lead-free piezoelectrics were discussed in relation to donor and acceptor modified PZTs, respectively. Technologically, the lead-free materials are discussed in relation to general applications, including sensors, actuators and ultrasound transducers.