高Curie温度(1-2x)PbNb_2O_(6)-xSrTiO_(3)-xTiO_2压电陶瓷

(1-2x)PbNb_2O_(6-x)SrTiO_(3-x)TiO_2 PIEZOELECTRIC CERAMICS WITH HIGH CURIE TEMPERATURE

采用传统电子陶瓷的制备方法制备了(1-2x)PbNb2O6-xSrTiO3-xTiO2(x=0.005～0.025)高Curie温度(θC)压电陶瓷。X射线衍射分析表明:所有样品在1250℃保温2h烧结均形成铁电性的斜方钨青铜型结构(tungsten bronze structure,TB)。相对介电常数-温度(εr-θ)曲线表明:该体系具有高的θC(500～560℃)。测试了不同掺杂量对陶瓷介电和压电性能的影响,发现材料的θC、压电常数(d33)和机电耦合系数(kp)随着x值的增加先增加后降低。当x=0.02时,陶瓷的d33达到最大值,为83pC/N,θC为550℃,kp达33.4%,材料的介电常数ε3θ3/ε0为217,为组成的最优配方。

Piezoelectric ceramics of （1-2x） PbNb2O6-xSrTiO3-xTiO2 （x=0.005-0.025） with high Curie temperature （θC） were fabricated by the conventional ceramic preparation technique. X-ray diffraction patterns indicate that all ceramics sintered at 1 250 ℃ for 2 h formed ferroelectric orthorhombic symmetric tungsten bronze structures. The results of dielectric constant vs temperature （εr-θ） analysis show that all the compositions have high θC in the range of 500-560 ℃ . The effect of SrTiO3 and TiO2 doping on dielectric and piezoelectric properties was investigated. It is found that the θC, the piezoelectric constant （d33） and electromechanical coupling factor （kp） increase first then decrease with the increasing of x value. When x equals 0.02, the piezoelectric ceramic has the best properties：d33=83 pC/N, θC=550 ℃ , kp=33.4%, and ε 3θ3/ε0 =217.