微纳米压电材料尺寸效应的物理机理研究

项目名称： 微纳米压电材料尺寸效应的物理机理研究

项目编号： No.11472313

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 王彪

作者单位： 中山大学

项目金额： 105万元

中文摘要： 随着近年纳米技术的发展，研究人员在实验中发现微纳米尺度下许多压电材料的压电性能与对应体材料相比存在显著差异，甚至一些原本不具备压电性能的体材料随着尺寸的降低与力学载荷形式的变化可能引发显著的类压电效应。这一发现有望推动纳尺度智能器件产业的新一轮发展，而其中的物理机制至今尚不明确。本项目拟利用第一性原理计算与实验观测相结合的手段揭示微纳米压电材料尺寸效应的物理机理，并在此基础上构建包含尺寸效应的压电材料热力学模型，达到通过体材料相关系数以及表面边界条件预报对应微纳尺度材料力电耦合系数的目的。项目分两部分展开，一是针对传统压电材料在微纳尺度下的尺寸效应的研究，二是针对在纳尺度下出现类压电效应的新型压电材料物理机理与临界尺寸的研究。本项目的研究具备多物理、多尺度的特点，对此进行深入研究有助推动传统力学、功能材料科学以及凝聚态物理学科的交叉发展。

中文关键词： 尺度效应；压电材料；表面效应；挠曲电效应；力电耦合

英文摘要： With the rapid development of nanotechnology in recent years, researchers found in experiments that for many piezoelectric materials, their piezoelectric properties examined within micro-nano-scale samples vary significantly from corresponding bulk materials. It is even seen that with decreasing sample size, obvious piezoelectric-like phenomenon is observed in bulkly non-piezoelectric materials. These findings provide an opportunity for a new round of development for nano-scale smart devices, yet the hidden physical mechanism is not clear so far. This project aims at uncovering the physical mechanism of the size effect in micro-nano-scale piezoelectric materials with combined first principle calculation and experimental observation. Based on the result, a thermodynamics model with size effect for piezoelectric materials is built, by which we can predict the effective electromechanical coupling coeffecients for any micro-nano-sized materials from their bulk piezoelectric constants and some mechanical and electric boundary conditions. The project is expanded into two parts, one on the size effect of traditional piezoelectric materials with micro-nano-scale; the other on the physical mechanism and critical size of new piezoelectric materials showing piezoelectric-like phenomenon at micro-nano-scale. The research of this project has the characteristics of multi physics and multi-scale; intensive study of the project will help the mutidisciplinary development of classic mechanics, functional materials science and condensed matter physics.

英文关键词： size effect;piezoelectric materials;surface effect;flexoelectricity;electromechanical coupling