Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3-PbZrO_3陶瓷在准同型相界附近的结构与性能研究

Structure and Electrical Properties of Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3-PbZrO_3 Ceramics Near Morphotropic Phase Boundary

基于Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT)和PbZrO3-PbTiO3(PZT)两个赝二元体系的准同型相界组分和线性组合规律,设计了一系列具有准同型相界组分的PMN-PT-PZ赝三元体系。采用传统的铌铁矿预合成法制备了各组分的铁电陶瓷,研究了它们的相结构及介电、压电和铁电性能。研究表明,该系列PMN-PT-PZ赝三元系铁电陶瓷都具有三方与四方相共存的准同型结构和优异的电学性能。其中,PZ含量为40%(摩尔分数)的0.16PMN-0.44PT-0.4PZ铁电陶瓷样品具有最佳的综合电性能,其室温介电常数εr为2014,压电常数d33为410 pC.N-1,机电耦合系数kp为0.58,剩余极化强度Pr为34.5μC.cm-2,矫顽场Ec为13.4 kV.cm-1。

On the basis of the respective compositions near the morphotropie phase boundary （MPB） region of Pb （ Mg1/3 Nb2/3 ） 03-PbTiO3 （PMN-PT） and PbZrO3- PbTiO3 （PZT）, a series of compositions of PMN-PT- PZ pseudo ternary system were selected according to the proposed linear combination rules. The PMN-PT- PZ ceramics were fabricated by the conventional eo- lumbite precursor method, and their phase structures, dielectric, piezoelectric and ferroelectric properties were investigated systematically. The obtained results indicated that all the selected PMN-PT-PZ ceramics located in the rhombohedral/tetragonal coexistence MPB region and had excellent electrical properties. The special interest was focused on the composition 0.16PMN-0.44PT-0.4PZ, and optimum comprehensive electrical properties of room temperature dielectric constant εr = 2014, piezoelectric constant d33 = 410 pC ·N^-1, electromechanical factor kp = 0.58, remanant polarization Pr = 34. 5 μC·cm^-2 and coercive field Ec = 1.98 kV .cm^- 1 were observed at this composition.