准同型相界附近PMN-PT陶瓷的介电与压电性能  

Dielectric and piezoelectric properties of PMN-PT ceramics near the morphotropic phase boundary

作　　者：曹林洪[1] 姚熹[2] 徐卓[2] 

机构地区：[1]西南科技大学先进建筑材料四川省重点实验室,四川绵阳621010 [2]西安交通大学电子材料研究所,陕西西安710049

出　　处：《材料热处理学报》2007年第3期1-5,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助(50472052;10474077)

摘　　要：采用铌铁矿预产物合成法制备了组成在相界附近的(1-x)Pb(Mg1/3Nb2/3)O3-x PbTiO3弛豫铁电陶瓷。陶瓷样品X射线衍射相组成和相结构分析表明:所有陶瓷样品均为纯钙钛矿相,没有检测出其它杂相;而且组成在x=0.33 mol处存在一准同型相界(MPB),在该相界附近三方相和四方相共存,而远离该相界则分别为纯三方相和四方相。在该相界附近组成具有优异的介电和压电性能:εm^38000,Ec^5kV/cm,Pr^31.5μC/cm2,d33~500pC/N,这主要是由于宏观上的三方和四方两相共存,或微观上的微畴和宏畴共存引起的。Relaxor ferroelectric (1-x) Pb (Mg1/3Nb2/3) O3-x PbTiO3 ceramics near the morphotropic phase boundary were prepared by the columbite precursor method. The phase composition and phase structure of ceramic samples were investigated by X-ray diffraction analysis. The results show that pure perovskite phase is obtained for all the specimens and no other phase is detected. Moreover, there exists a morphotropic phase boundary (MPB) for the composition at x = 0.33mol, and the rhombohedra phase and tetragonal phase coexists for the composition near MPB, but the pure rhombohedra phase and tetragonal phase separately exists for the composition away from MPB. Furthermore, the ceramics near MPB exhibits excellent dielectric and piezoelectric properties, such as Εm-38000, Ec-5 kV/cm, Pr-31.5μC/cm2, d33-500 pC/N. This is mainly ascribed to macroscopic coexistence of rhombohedra phase and tetragonal phase, or microcosmic coexistence of microdomain and macrodomain.

关 键 词：铌镁酸铅-钛酸铅(PMN-PT)陶瓷 铌铁矿预产物合成法 准同型相界 介电与压电性能 

分 类 号：TM282[一般工业技术—材料科学与工程]