(1-x)BiScO3-xPbTiO3陶瓷(简记BS-PT)在x=64.0%附近存在一个从菱方晶系过渡到四方晶系的准同型相界,在此相界附近材料能获得优良的介电和压电性能.本文选取PbTiO3含量在64.0%-65.5%的准同型相界附近的材料组分,利用传统的固相烧结反应法合成了纯钙钛矿相结构的BS—PT陶瓷,通过对材料的相结构形成过程和内部形貌分析以及对介电、压电性能的研究,发现在x=64.5%的组分条件下,BS—PT陶瓷材料获得了准同型相界范围内的最优的压电性能,其室温压电常数d33可达500pC/N,且居里温度(Tc)达到了438℃,剩余极化强度和电致应变分别为44μC/cm^2和3.5‰.研究表明,准同型相界附近的BS-PT陶瓷是一种优良的压电换能器和传感器材料.
Abstract: (1-x)BiScO3-xPbTiO3 (BS-PT) ceramics exhibits excellent dielectric and piezoelectric properties in the vicinity of the morphotropic phase boundary (x=64.0% mol fraction PbTiO3), which separates the rhombohedral phase from tetragonal phase. In our study, the pure perovskite BS-PT ceramics was obtained with compositions near the MPB for x varying from 64.0% to 65.5% using traditional solid state reaction. The perovskite phase formation process and microstructure were investigated and also the dielectric and piezoelectric properties were studied. The results show that BS-PT ceramics with x=64.5% has an optimized piezoelectric characterization, its piezoelectric coefficient d33 can reach to as high as 500 pC/N at room temperature, the Curie temperature (Tc) can reach to 438℃, with the remnant polarization Pr=44μC/cm^2, electrical field reduced strain 3.5 %0. Our research results show that the BS-PT ceramics with the compositions near the morphotropic phase boundary is a good candidate material for the piezoelectric actuator and transducers.