高温压电传感器是监测高温环境下各类装备振动状态的核心元件；而制作这类元件的关键材料是高居里温度压电陶瓷。铌酸铋钙[CaBi2Nb2O9(CBN)]陶瓷居里温度高达940℃，在高温压电领域有重要应用潜力。目前的研究表明稀土离子掺杂能够有效地增强CBN陶瓷的压电性，但缺乏对掺杂CBN陶瓷中缺陷和电性能关联性的系统研究。缺陷对陶瓷性能有非常重要的影响。本项目将从缺陷切入，研究稀土掺杂CBN陶瓷缺陷形态和缺陷控制，以期通过控制陶瓷缺陷实现电性能的优化。重点解决如下三个关键科学问题:1)设计制备稀土掺杂CBN陶瓷，定位稀土离子位置，识别缺陷形态；2)研究高温下稀土掺杂CBN陶瓷的缺陷运行模式，建立缺陷运动模型，认识缺陷运动与电性能的关联机理；3)掌握通过缺陷设计来实现高温压电性能定向优化的方法。本项目能够为新型高温压电材料中缺陷的设计与控制、性能优化以及相关器件研制提供理论及实验支撑。

High temperature piezoelectric sensors are the core components to monitor the vibration state of many equipments operating in high temperature environment. High Curie-temperature piezoelectric ceramics are the key materials for these sensors. Calcium bismuth niobate [CaBi2Nb2O9 (CBN)] with an ultra-high Curie temperature (~940℃) has important potential in high temperature piezoelectric applications. It is reported that the rare-earth dopants effectively enhance the piezoelectric properties of CBN-based ceramics. Unfortunately, the research on the relationship between defects and electrical properties is scarce. The properties of ceramics are strongly influenced by defects. This project will study the defect morphologies of rare-earth modified CBN-based ceramics and optimize the electrical properties by controlling the ceramic defects. The study will solve the following three primary problems: 1) design and synthesize rare earth ions doped CBN ceramics, locate the defects and identify the defect morphologies; 2) investigate the transition behavior of defects and corresponding mechanism of electrical properties; 3) acquire the method to distinctively optimize electrical properties by tailoring the internal defects. This project can provide theoretical and experimental support for the design and control of defects, performance optimization in the new high temperature piezoelectric materials, and the development of related devices.