Crystal structures and piezoelectric properties of PbZrO₃-PbTiO₃-Pb(Ni_1/3Nb_2/3)O₃ ceramics near the triple point composition, particularly characteristics of the pseudocubic phase, were investigated. The pseudocubic phase, which formed near the triple point composition, disappeared with increase in the PbZrO₃ content. The pseudocubic phase had the Pm3m cubic structure. The tetragonal-pseudocubic morphotropic phase boundary (MPB) structure was developed during the tetragonal-to-cubic phase transformation. However, the rhombohedral phase directly transformed to the cubic phase because the structure of pseudocubic phase was similar to the rhombohedral structure. The specimens with pseudocubic phase and the specimens near pseudocubic phase exhibited nano-sized domains and small coercive electric fields, revealing their low domain wall energies. These specimens exhibited second-order ferroelectric-to-paraelectric phase transition and low Curie temperatures, confirming their low domain wall energies. The enhanced dielectric and piezoelectric properties of these specimens could be attributed to their low domain wall energies.

研究了接近三点组成的PbZrO ₃ -PbTiO ₃ -Pb（Ni _1/3 Nb _2/3）O ₃陶瓷的晶体结构和压电性能，特别是假立方相的特性。随着PbZrO ₃含量的增加，在三点组成附近形成的假立方相消失了。伪立方相的Pm3m立方结构。四方-立方相变过程中形成了四方-准双相向相界（MPB）结构。但是，由于假立方相的结构类似于菱面体的结构，菱面体相直接转变为立方相。具有伪立方相的样品和接近伪立方相的样品显示出纳米尺寸的畴和小的矫顽电场，显示出它们的低畴壁能量。这些样品表现出二阶铁电至顺电的相变和居里温度低，证实了它们的低畴壁能量。这些样品的增强的介电和压电性能可以归因于其低畴壁能量。