Mechanism of large piezoelectric response due to special anisotropy near the morphotropic phase boundary in ferroelectric materials

本研究的目的是澄清复杂钙钛矿铁电体Pb（Zn_（11）3）Nb_（2，3）O_3-PbTiO_3（PZN-PT）中作为平均结构的稳定相。本文研制了一套在800 V左右直流偏置电压下测量100 Hz ~ 1 MHz范围内介质色散的装置。阐明了PZN-PT中[001]、[011]、[111]方向电场沿着方向的电场-温度相图。在沿着[001]方向上，发现临界终点在1 kV/cm左右，这是相当小的，同时发现相图的形状强烈地依赖于电场的方向。

The purpose of our study is that stable phases as an average structure in complex perovskite ferroelectrics Pb(Zn1i3 Nb2,3)O3- PbTiO3 (PZN-PT) are clarified. In the present study, the equipment to measure the dielectric dispersion between 100 Hz to 1MHz under the DC biasing voltage of about 800 V was composed. The electric field-temperature phase diagrams in the electric field along the [001], [011], [111] directions in PZN-PT were clarified. Along [001] direction, the critical end point at about 1 kV/cm, which is considerably small, was found. It was also found that aspect of phase diagrams strongly depends on the direction of the electric field.