基于PMN-PT单晶的层状结构中弹性波传播特性研究

项目名称： 基于PMN-PT单晶的层状结构中弹性波传播特性研究

项目编号： No.11272221

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 聂国权

作者单位： 石家庄铁道大学

项目金额： 86万元

中文摘要： 弛豫铁电单晶PMN-PT的压电常数、机电耦合系数和应变量均远远超过目前广泛应用的压电陶瓷，是制作新一代压电超声换能器、传感器、驱动器和致动器的理想材料。与压电陶瓷不同，PMN-PT单晶的宏观对称性与其极化方向有关，而且具有较强的各向异性，弹性波在其中的传播呈现出许多特殊的现象，各种波型强烈耦合，频散曲线非常复杂。鉴于此，本项目将对压电声波器件的几种典型构型（层状结构和周期复合结构）中的表面波、界面波和导波开展较为系统的研究，揭示弹性波在材料或结构表面或界面传播、反射和折射的基本规律，分析各种因素对弹性波传播特性的影响。在此基础上，进一步考虑外部场和环境因素，如任意分布的预应力、电场以及流体载荷作用情况，研究弹性波的传播性能，并通过实验验证层状结构中导波理论解的正确性。研究成果可为基于PMN-PT单晶的各种声波和微波器件的优化设计和工程应用提供理论基础。

中文关键词： PMN-PT单晶；层状结构；弹性波；频散关系；机电耦合

英文摘要： The properties of relaxor ferroelectric PMN-PT single crystal, such as piezoelectric constant, electromechanical coupling coefficient, and strain capacity, are much greater than those of piezoelectric ceramics. From fabrication consideration, PMN-PT single crystals are more favored in the next generation electromechanical devices, including piezoelectric ultrasonic transducers, sensors, actuators, ultrasonic motors, etc. PMN-PT single crystal has the property of strong anisotropy and their macroscopic symmetry depends on the polarizing direction, which is different from the transversely isotropic piezoelectric ceramics. Duo to this fact, more particularities and complexities of the elastic waves propagating in such materials and corresponding sturctures would be considered. The various wave modes are strong coupling and the dispersion curves are more intricate. The layered and periodic structures are often used in acoustic wave device, and thus, this project will focus on the surface wave, interface wave and guided wave propagating in these typical structures consisting of PMN-PT single crystal and other elastic media. The characteristics of propagation, reflection, and refraction of elastic wave in the surface and interface of the composite structures will be drawn based on the analysis of various influence fac

英文关键词： PMN-PT single crystal；Layered structure；Elastic wave；Dispersion relation；Electromechanical coupling