【作者】 刘妍；

【导师】 刘韩星；

【作者基本信息】 武汉理工大学 ， 材料物理与化学， 2010， 硕士

【摘要】 科学技术的飞速发展对压电器件在高温环境下的使用提出了要求,目前商业化应用的锆钛酸铅体系压电陶瓷材料的居里温度较低,安全使用温度被限制在150℃以内,因此开发具有优良压电性能的高居里温度压电陶瓷材料成为国内外研究的热点。BiScO3-PbTiO3体系在准同型相界处具有很高的居里温度和优良的压电性能,是一类出色的高温压电陶瓷材料；Pb(Mg1/3Nb2/3)O3-PbTiO3体系压电陶瓷在准同型相界处的压电性能非常优异,但是居里温度很低只有150℃。本论文针对上述问题,向BSPT体系中引入PMN,以PMN-BS-PT三元体系为研究对象,控制PMN的引入量为10mol.%和5mol.%,分别研究了0.1PMN-BS-PT和0.05PMN-BS-PT两个体系在准同型相界附近的结构与性能,探讨了PMN的引入对体系的影响。研究发现,O.1PMN-BS-PT体系在PT含量较低时表现出明显的铁电弛豫特性,随着PT含量的增加,逐渐转变为正常铁电体；而0.05PMN-BS-PT体系由于PMN的含量较低并没有表现出明显的铁电弛豫特性。随着PT含量的增加,两个体系的居里温度均逐渐升高,矫顽场逐渐增大,剩余极化强度先增大后减小。0.1PMN-BS-PT体系在PT含量为56%处获得准同型相界区域性能最优点,其性能为：压电常数d33=387pC/N,机电耦合系数kp=0.49,居里温度Tc=361℃,矫顽场Ec=20.64kV/cm,剩余极化强度Pr=31.88μC/cm2; 0.05PMN-BS-PT体系在PT含量为59%处获得准同型相界区域性能最优点,其性能为：压电常数d33=487pC/N,机电耦合系数kp=0.59,居里温度Tc=404℃,矫顽场Ec=22.31kV/cm,剩余极化强度Pr=34.73μC/cm2。可见,PMN的引入降低了体系的居里温度；10%的引入量使得体系变“硬”,降低了体系的压电性能；而减少引入量至5%时软化作用占优,增加了体系的压电性能。更多还原

【Abstract】 With the rapid development of science and technology, more piezoelectric devices should be used in high-temperature environment. Commercial PZT piezoelectric ceramics have a low curie temperature, whose working temperature(< 150℃) is too low to be used in practice. So the current researches are focused on investigating and developing high curie temperature piezoelectric ceramics. As a kind of excellent high curie temperature piezoelectric ceramics, BiScO3-PbTiO3 system ceramics at MPB exhibit high curie temperature and piezoelectric properties. Pb(Mg1/3Nb2/3)O3-PbTiO3 system ceramics have excellent piezoelectric properties at MPB with low curie temperature(150℃).Addressed these issues, we introduce PMN to BSPT system, and the PMN-BS-PT ternary system ceramics with 10mol.%PT and 5mol.%PT were studied in this paper. Through the research of structure and properties near the two MPBs, we discussed the affect of PMN as a third component to the system.The results show that 0.1 PMN-BS-PT system with low PT content indicate a typical character of relaxor ferroelectrics, and it is transformed into normal ferroelectrics as increasing of PT content. Because of the low PMN content, 0.05PMN-BS-PT system doesn’t indicate a typical character of relaxor ferroelectrics. With the growing of PT content, the curie temperature and coercive field of the two system increase, but the remanent polarization firstly increase and then decreasing. When the PT content is 56mol.%, the 0.1 PMN-BS-PT system show the optimal piezoelectric properties with d33=3/7pC/N, kp=0.49, Tc=361℃,Ec=20.64kV/cm, Pr=31.88μC/cm2. The 0.05PMN-BS-PT system with 59mol.% PT indicate the optimal piezoelectric properties with d33=487pC/N,kp=0.59, Tc=404℃, Ec=22.31kV/cm,Pr=34.73μC/cm2. So the introduction of PMN reduce the curie temperature; 10mol.% PMN indicate the“hard”behavior as a functon of reducing the piezoelectric properties; 5mol.% PMN indicate the“soft”behavior with increasing the piezoelectric properties.更多还原