Max Planck Institut für Festkörperforschung, Stuttgart, Germany.
J Phys Condens Matter. 2013 May 29;25(21):212202. doi: 10.1088/0953-8984/25/21/212202. Epub 2013 May 3.
To better understand the phase transition mechanism of PbZrO3 (PZO), the lattice dynamics of this antiferroelectric compound are investigated within the polarizability model, with emphasis on the cubic to orthorhombic phase transition. Similarly to ferroelectric phase transitions in ABO3 perovskites, polar dynamical clusters develop and grow in size upon approaching T(C) from the high temperature side and never form a homogeneous state. Simultaneously, elastic anomalies set in and compete with polar cluster dynamics. These unusual dynamics are responsible for precursor effects that drive the PZO lattice towards an incipient ferroelectric state. Comparison of the model calculations with the temperature dependences of elastic coefficients measured on PZO single crystals reveals a striking similarity.
为了更好地理解 PbZrO3（PZO）的相变机制，在介电常数模型的基础上对这种反铁电化合物的晶格动力学进行了研究，重点研究了立方到正交相的转变。与 ABO3 钙钛矿的铁电相变类似，在高温侧接近 T(C)时，极性动力学团簇会发展和增大，但永远不会形成均匀状态。同时，弹性异常也会出现，并与极性团簇动力学竞争。这些异常的动力学是导致 PZO 晶格向初始铁电状态发展的前驱效应的原因。模型计算与在 PZO 单晶上测量的弹性系数的温度依赖性的比较显示出惊人的相似性。
