低钪BSPT高温压电陶瓷的气氛烧结及其高温电导机理研究

BiScO3 - PbTiO3 (BSPT) piezoelectric ceramics with high Curie temperature and high piezoelectric performance could be applied for high temperature piezoelectric sensors and, therefore, becomes a research hotspot in current novel piezoelectric and ferroelectric researches. However, the high cost of Sc2O3 and the large conductivity at high temperatures for BSPT ceramics have restricted the application of this material system. This project aims at BSPT-based piezoelectric ceramics with low scandium content and focuses on two key scientific problems, namely, "high temperature conductance mechanism" and "atmosphere sintering mechanism as well as its inhibition of oxygen vacancies and defects". Accordingly, low-scandium-content BSPT based piezoelectric materials will be prepared by the solid state reaction method with atmosphere sintering; then, the material composition, structure, and electrical properties will be characterized respectively by XPS, XRD, and high temperature conductivity testing instruments; thus, the high temperature conductivity mechanism, the densification process and the inhibition mechanism of oxygen vacancies and defects during the atmosphere sintering will be grasped for low-scandium-content BSPT based piezoelectric ceramics; eventually, high temperature vibration sensor prototype devices will be tentatively fabricated using the low-scandium-content BSPT based high temperature piezoelectric ceramics. More than 8 SCI/EI-indexed papers will be published; 1~2 national invention patents will be applied or granted; 2~3 young teachers will be cultivated for western universities. We are confident that this project is important and urgent because it is significant for the study of novel high temperature piezoelectric materials and development of high temperature piezoelectric sensors.

BiScO3-PbTiO3（BSPT）压电陶瓷具有居里温度高、压电性能好，可望应用于高温压电传感器，是当前国际新型压电铁电研究热点之一。但Sc2O3成本高、BSPT陶瓷高温电导率大，制约了该材料体系的应用。本项目瞄准低钪BSPT基压电陶瓷，针对"高温电导机理 "、"气氛烧结机制及其对氧空位、缺陷抑制机理"两个关键科学问题开展研究；采用固相反应气氛烧结法制备低钪BSPT基压电材料；采用XRD、XPS、高温电导测试仪等表征材料组分、结构、电学性能；掌握低钪BSPT基压电陶瓷高温电导机理；掌握气氛烧结低钪BSPT基陶瓷的致密化过程及其对氧空位、缺陷的抑制机理；利用低钪BSPT基高温压电陶瓷试制高温振动传感原型器件。发表SCI、EI收录论文8篇以上；申请或获授权国家发明专利1~2项；为西部高校培养青年教师2~3人。本项目重要、紧迫，对研究新型高温压电材料、发展高温压电传感器具重要意义。

BiScO3-PbTiO3（BSPT）压电陶瓷具有居里温度高、压电性能好，可望应用于高温压电传感器，是当前国际新型压电铁电研究热点之一。本项目针对"高温电导机理"、"气氛烧结机制及其对氧空位、缺陷抑制机理"两个关键科学问题开展研究，采用XRD、SEM、介温测试仪等表征了材料的结构和电学性能，结论如下：1）采用固相反应研究了Fe2+/3+、Mg2+、Ba2+等离子高含量掺杂对BMPT高温压电陶瓷电学性能的影响，实验表明BaTiO3第三方引入有助于BiFeO3-PbTiO3的烧结行为；2）采用固相反应首次研究了0-3型(1-x)(0.30BiFeO3-0.70PbTiO3)/x(0.36BiScO3-0.64PbTiO3)复合矩阵陶瓷固溶体系(x=0.2, 0.4, 0.6, 0.8)，实验发现陶瓷样品皆为纯四方相钙钛矿结构。0-3型复合陶瓷的压电性能随x的增加而增加，压电常数分别为196，247，288，和311pC/N；居里温度Tc随x的增加而增加，分别为320，400，410和430℃。0-3型复合体系具有剩余磁化强度Mr~0.04emu/g。3)采用低温固相反应研究了(1-x)(0.36BiScO3-0.64PbTiO3)-xM，M为助熔剂体系（B2O3、Bi2O3、SiO2、ZnO）（x=0.01，0.02，0.03，0.04，0.05）。实验研究了烧结温度对BSPT陶瓷电学性能的影响，当烧结温度为900℃时，BSPT获得了纯ABO3钙钛矿结构，其压电常数分别为234，185，176，113和105pC/N，表明M助熔剂对BSPT具有明显的助烧作用。该体系的居里温度为430~450℃，该研究成果可通过低温共烧技术实现高温设备小型化；4）采用气氛烧结制备(1-x)CaBi4Ti4O15-xBiScO3高温无铅高温压电陶瓷(x=0.01, 0.005, 0.0025)，其居里温度达到675℃，d33~22pC/N；实验揭示了富氧气氛烧结温度与高温压电陶瓷的稳定性的关系，该研究成果在高温传感器方面极具推广价值；发表SCI、EI收录论文2篇，核心期刊1篇，投稿5篇；获批实用新型专利3项，申请国家发明专利2项；“高温压电陶瓷材料及应用研究”获得了贵州省科技进步三等奖；出版教材2本；培养青年教师4人；本项目的实施成果对研究新型高温压电材料、发展高温压电传感器具重要意义。