PbTiO3在压力下的异常相变和极强压电效应

运用第一性原理计算预言了在一纯化合物中可由压力诱导出顺序为叫方晶-单斜体-菱形体-立方体的新的相变，而且存在有变形相界面。在相变区有可与在复杂的单晶固溶体压电材料，如人们期待在机电应用方面引起革命性变化的Pb（Mg1/3Nb2/3）O3-PbTiO3可比的，极大的介电和压电耦合常数。我们的结果表明变形相界面和巨压电效应并不需要内禀的无序，并打开了在简单系统中研究这一效应的可能性，

Pressure-induced anomalous phase transitions and colossal enhancement of piezoelectricity in PbTiO3

An unexpected tetragonal-to-monoclinic-to-rhombohedral-to-cubic phase transition sequence induced by pressure and a morphotropic phase boundary in a pure compound has been predicted by first-principles calculations.Huge dielectric and piezoelectric coupling constants occur in the transition regions,comparable to those observed in the new complex single-crystal solid-solution piezoelectrics such as Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3,which are expected to revolutionize electromechanical applications.Our results show that morphotropic phase boundaries and giant piezoelectric effects do not require intrinsic disorder,and open the possibility of studying this effect in simple systems.