铁电马氏体中的电致形状记忆效应

与温度驱动形状记忆的缓慢响应及磁场驱动形状记忆的巨大体积相比较，电场驱动形状记忆具有响应快和体积小的优点。但是，基于传统反压电效应的电场驱动形状记忆由于变形量较小而收到限制。本研究表明，通过运用基于点缺陷短程序对称性遵循的普适性原理的可逆畴翻转机制，可以在铁电马氏体中获得巨大的电致形状记忆效应；其产生的变形量理论上是反压电效应所产生变形量的几十倍。采用原位畴观察实验给出了可逆畴翻转的直接证据。并且，在铁电多晶陶瓷中也获得了这种大的电致形状记忆效应。这种效应在很宽的频率范围内都很稳定，在疲劳测试中也显示了很好的可靠性。运用这一新的电致形状效应有望制备出新一代非线性驱动器材料。

ELECTRO-SHAPE-MEMORY EFFECT IN FERROELECTRIC MARTENSITE

Compared with the slow response of temperature-driven shape memory and bulky magnetic-driven shape-memory systems, the electric-driven shape-memory has advantage of "quick and slim actuation". Electric-driven shape memory by conventional converse piezoelectric effect is restricted by the small effect. In the present paper we show that by utilizing a defect-mediated reversible domain switching mechanism, it is possible to achieve a large electro-shape-memory effect in ferroelectric martensite system, which is over one order of magnitude larger than conventional converse piezoelectric effect. Direct evidence for the reversible domain switching process is obtained by in-situ domain observation. Furthermore, similar effect is also found in ferroelectric poly-crystals/ ceramics, which shows good stability over a wide frequency range and high reliability against field cycling. The new electro-shape-memory effect may have promising application potential in non-linear actuators.