铁电唯象理论在压电单晶工程化畴研究中的应用

Application of Ferroelectric Phenomenological Theory in Engineered Domain Configurations of Piezoelectric Single Crystal

本文运用朗道—德文希尔自由能函数计算了钙钛矿型固溶体压电单晶在自发极化方向的压电常数d3 3 及工程化畴化方向的压电常数d′3 3 。研究结果表明 ,工程化畴方向具有比自发极化方向更优越的压电性能 ,当晶体的成分越靠近准同型相界的时候其压电常数越大 。

The piezoelectric constants d ′ 33 under three types of engineered domain configurations in perovskite type piezoelectric single crystals were calculated in terms of the Landau Devonshire type free energy function.It was found that the piezoelectric constant under the engineered domain configuration is much better than that of along the direction of the spontaneous polarization,and also increasing on approaching the morphotropic phase boundary.The anomaly in the piezoelectric constant under the engineered domain configuration for crystals near the morphotropic phase boundary should attribute to the instability of the dielectric constant perpendicular to the spontaneous polarization.