Materials Research Institute, The Pennsylvania State University, University Park, PA, USA.
IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Oct;57(10):2138-46. doi: 10.1109/TUFFC.2010.1670.
Relaxor-PT based ferroelectric single crystals Pb(Zn₁/₃)Nb(₂/₃)O₃-PbTiO₃ (PZNT) and Pb(Mg₁/₃)Nb(₂/₃)O₃-PbTiO₃ (PMNT) offer high performance with ultra-high electromechanical coupling factors k₃₃ > 0.9 and piezoelectric coefficients d₃₃s > 1500 pC/N. However, the usage temperature range of these perovskite single crystals is limited by T(RT)-the rhombohedral to tetragonal phase transition temperature, which occurs at significantly lower temperatures than the Curie temperature T(C), a consequence of curved morphotropic phase boundaries (MPBs). Furthermore, these <001>-oriented crystals exhibit low mechanical quality Q and coercive fields, restricting their usage in high-power applications. In this survey, recent developments on binary and ternary perovskite relaxor-PT crystal systems are reviewed with respect to their temperature usage range. General trends of dielectric and piezoelectric properties of relaxor-PT crystal systems are discussed in relation to their respective T(C)/T(RT). In addition, two approaches have been implemented to improve mechanical Q, including acceptor dopants, analogous to hard polycrystalline ceramics, and anisotropic domain engineering, enabling low-loss crystals with high coupling for high-power applications.
基于弛豫铁电体的单相晶体 Pb(Zn₁/₃)Nb(₂/₃)O₃-PbTiO₃（PZNT）和 Pb(Mg₁/₃)Nb(₂/₃)O₃-PbTiO₃（PMNT）具有超高机电耦合系数 k₃₃>0.9 和压电系数 d₃₃s>1500 pC/N 的优异性能。然而，这些钙钛矿单相晶体的使用温度范围受到 T(RT)的限制，即三方相到四方相的相变温度，其发生温度明显低于居里温度 T(C)，这是由于形态相变边界（MPB）的弯曲所致。此外，这些<001>取向的晶体表现出较低的机械品质因数 Q 和矫顽场，限制了它们在高功率应用中的使用。在本综述中，针对其温度使用范围，对二元和三元钙钛矿弛豫铁电体晶体系统的最新进展进行了回顾。讨论了弛豫铁电体晶体系统的介电和压电性能的一般趋势，以及它们各自的 T(C)/T(RT)之间的关系。此外，已经实施了两种方法来提高机械 Q，包括类似于硬多晶陶瓷的受主掺杂和各向异性畴工程，从而为高功率应用提供具有高耦合的低损耗晶体。
