|About this Abstract
||Materials Science & Technology 2012
||Advances in Dielectric Materials and Electronic Devices
||Large Piezoelectric Effect in Pb-Free MPB System Ba(Ti0.8Hf0.2)O3-(Ba0.7Ca0.3)TiO3
||Chao Zhou, Wenfeng Liu, Dezhen Xue, Xiaobing Ren, Huixin Bao, Jinghui Gao, Lixue Zhang
|On-Site Speaker (Planned)
We report a newly discovered Pb-free piezoelectric system – Ba(Ti0.8Hf0.2)O3-(Ba0.7Ca0.3)TiO3 (BHT-xBCT), which is designed upon a triple-point morphotropic phase boundary (TMPB) idea. The optimal composition of the system - BHT-0.5BCT shows excellent piezoelectricity around TMPB with d33 achieving ~550 pC/N at room temperature, exceeding most of the current Pb-free piezoelectrics. Moreover, theoretical analysis and experimentally detected non-zero thermal hysteresis around triple point both demonstrate a first order nature transition and non-isotropic polarization state, which are actually the basic assumptions in much previous related work. Our study indicates a universal effective way to obtain piezoelectrics with good piezoelectricity by constructing TMPB, and may also stimulate the study on triple-point related critical phenomena in other ferroic systems.