无铅铁电单晶的压电活性与结构本质

项目名称： 无铅铁电单晶的压电活性与结构本质

项目编号： No.51332009

项目类型： 重点项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 罗豪甦

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 290万元

中文摘要： 围绕以钛酸铋钠（NBT）基、铌酸钾钠（KNN）基为代表的钙钛矿型铁电固溶体单晶高压电活性及其结构本质研究，包括高压电性能、低介电损耗、高温度稳定性无铅铁电材料的设计、制备、结构与性能调控机理，开展铁电单晶生长，与单晶材料多层次多尺度结构对本征压电性能和非本征压电性能的影响规律研究；结合同步辐射、透射电镜、拉曼光谱、压力电学显微镜、偏光显微镜等不同手段，研究无铅压电单晶的多层次多尺度（晶格畸变→偶极子→极化团簇→微畴→宏畴→相结构）结构特征与相变规律，揭示无铅压电单晶在外场（温度、电场、应力）作用下压电响应机理与结构本质；以及通过离子掺杂、气氛退火与极化后处理来调控材料多层次结构与压电性能。在此基础上，指导新型高性能无铅压电材料的设计和制备，以及现有无铅压电材料的改性研究，促进尽早实现压电材料无铅化的发展目标。

中文关键词： 铁电体;无铅压电材料;钙钛矿型结构;准同型相界;固溶体

英文摘要： The origin of piezoelectric response is investigated to their hierarchical structure in lead-free ferroelectric single crystals, such as NBT- and KNN-based solid sulution ferroelectrics. The project aims at to design and fabricate new ferroelectric single crystals with high piezoelectric response, low dielectric loss and high temperature stability, and the mechanism how to control the hierarchical structure and optimize their intrinsic and extrinsic piezoelectric performances. The hierarchical structure (lattice distortion→dipole→polar nano regions→nano-domains→macro-domains→phase structure) will be investigated multidimensionally by different techniques such as synchrotron X-ray radiation, transmission electron microscopy (TEM), raman spectrum, piezoelectric force microscope(PFM), polarized light microscopy (PLM) etc. The piezoelectric response will be investigated systematically in chemical composition, order and disorder of solid-solution and external field (such as temperature, strain and electric field) related to their hierarchical structure. Ionic-doping and post-process by atmosphere annealing and poling will be investigatd to optimize the piezoelectric properties of lead-free piezoelectric single crystals. We hope to have better understanding of the mechanism of piezoelectric response to find the fundamental difference between the lead-based MPB and lead-free MPB to design and fabricate novel high performance lead-free piezoelectric materials, and to make the contribution to eliminating lead-based piezoelectric materials eventually in the world.

英文关键词： ferroelectric;lead-free piezoelectric;perovskite;morphotropic phase boundary;solid solution