Ba取代对四元系PMNS-PZT压电陶瓷结构和电学性能的影响

STUDY OF THE EFFECTS OF Ba SUBSTITUTION ON THE STRUCTURE AND ELECTRICAL PROPERTIES OF PMNS-PZT QUATERNARY SYSTEM PIEZOELECTRIC CERAMICS

采用铌铁矿先驱体法制备了 Pb_(1-x)Ba_x(Zr_(0505)Ti_(0495))_(095)(Mn_(1/3)Nb_(1/3)Sb_(1/3))_(0.05)O_3(其中 x=0.01,0.02,0.03,0.04)四元系陶瓷,并考察了 Ba取代量变化对 PMNS-PZT 四元系陶瓷结构和性能的影响。XRD 测试结果表明,采用先驱体法合成 PMNS-PZT 陶瓷材料,为完全的钙钛矿结构,且随着 Ba 取代量的增加,经历了从四方-三方相共存再到完全三方相的相变过程,其准同型相界区间位于 x=0.01～0.03范围内。SEM 测试结果表明,Ba 取代量的变化对样品的显微组织结构影响不大,这应该是由于 Ba^(2+)取代量较低,在晶界处富集很少,对晶粒的长大抑制作用不明显所致。在 Ba^(2+)的取代量为3mol%时,其性能可达 K_p=0.50,Q_m=1385,d_(33)=255PC/N,ε~T_(33)/ε_0=1273,tan δ=0.52%,能满足大功率的要求。

Pb1-xBax（Zr0.505Ti0.495）0.95（Mn1/3Nb1/3Sb1/3）0.05O3 （PMNS-PZT, x=0.01, 0.02, 0.03, 0.04） ceramics have been prepared by a columbite precursor method. The crystal structure of the quaternary system ceramics was examined by using X-ray diffraction （XRD）. It was found that the crystal structure of the quaternary system ceramics prepared by columbite precursor method is pure pervoskite structure. It was also found that the morphotropic phase boundary （MPB） with rhombohedra and tetragonal co-existed crystalline structure for the ceramics lies in the range of x=0.01-0.03. When x〉0.03, the crystal structure of the ceramics is rhombohedra structure. The microstructure of the specimens was investigated by a JEOL JSM5610LV scanning electron microscope （SEM）. Homogeneous and dense microstructure of the system ceramics showing grain sizes of 1-3μm by SEM images, the grain growth inhibitory effect of Ba2＋is not so obvious. The piezoelectric, ferroelectric and dielectric properties of the quaternary system ceramics were investigated as functions of x. When Ba^2＋=3mol%,the preferred properties of Kp=0. 50, Qm= 1385, d33=255,ε^T33/E0=1273,tanδ=0.52% can be obtained, which can be used for ultrasonic motors.