Sr和Nb复合掺杂Bi4Ti3O12基高温压电陶瓷的研究

Sr and Nb Co-doped Bi_4Ti_3O_(12)-based High Temperature Piezoelectric Ceramics

采用传统固相法制备了Bi4Ti3O12+0.91wt%Nb2O5+xwt%SrCO3(BTNO-Sr,0.00≤x≤1.50)层状压电陶瓷,研究了Sr掺杂对BTNO系陶瓷微观结构与电性能的影响。结果表明所有样品均为单一的铋层状结构相陶瓷。适量引入Sr能使BTNO系陶瓷的晶粒尺寸细化与均一,表现出介电弥散性,并改善其压电﹑机电和铁电性能。当x=0.50时,样品性能最佳:相对密度ρ=98.8%,压电常数d33=22 pC/N,平面机电耦合系数kp=9.5%,机械品质因子Qm=4462,剩余极化强度Pr=13.01μC/cm2,居里温度Tc=620℃。此外,介电性能和热稳定性能研究显示材料x=0.50具有好的压电稳定性,适合于制备高温高频压电器件。

Abstract： Bismuth layer-structured ferroelectric ceramics ofBi4Ti3O12＋0.91wt%Nb2O5＋xwt%SrCO3（BTNO-Sr,0.00≤x≤1.50） were synthesized by traditional solid state reaction. The effects of Sr addition on the microstructure and electrical properties of ceramics were studied. The results indicated that all ceramics have a bismuth oxide layered structure. After Sr doping, the size of grain becomes small and unanimous. The diffuse phase transition behaviorwas observed, meanwhile, the piezoelectric, electromechanical and ferroelectric properties of BTNO-based ceramics were improved by an appropriate mnount of Sr addition. When x = 0. 50, the ceramic achieves an optimum performance： the relative density p = 98. 8 %, piezoelectric constant d33 = 22 pC/N, planar electromechanical coupling coeltlcient kp =9. 5 %, mechanical quality factor Qm =4462, remanent polarization Pr= 13.01 μC/cm^2, and Curie temperature Te =620 ℃. Moreover, the researches on dielectric properties and thermal annealing indicate that the ceramic with composition of x = 0. 50 possesses high piezoelectric stability, demonstrating that the ceramic is suitable for high-temperature and high-frequency piezoelectric devices.