Splitting of the transition to the antiferroelectric state in PbZr 0.95 Ti 0.05 O 3 into polar and antiferrodistortive components
Splitting of the transition to the antiferroelectric state in PbZr 0.95 Ti 0.05 O 3 into polar and antiferrodistortive components
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DOI：
10.1103/physrevb.88.094107
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发表时间：
2013-09
影响因子：
3.7
通讯作者：
F. Cordero;F. Craciun;F. Trequattrini;C. Galassi;P. Thomas;D. Keeble;A. M. Glazer
中科院分区：
文献类型：
--
作者：
F. Cordero;F. Craciun;F. Trequattrini;C. Galassi;P. Thomas;D. Keeble;A. M. Glazer
通过弹性、介电和 X 射线衍射测量，研究了陶瓷 PbZr1−xTixO3 在成分 x=0.05 接近反铁电正交 Pbam 和铁电菱面体相之间的同形相边界时的相变。不同速率的温度扫描表明，从 R3m 到 Pbam 的转变动力学非常缓慢，并且实际上分裂成较慢的极性分量（出现在介电磁化率中）和非极性分量（表现为杨氏模量的急剧硬化）。后者归因于 Pbam 相的氧八面体倾斜模式的建立，并且在随着冷却速率增加而降低的温度下立即发生。加热时，转变发生的温度比准静态冷却时高 65 K，因此两个组分几乎同时以更快的速率发生。杨氏模量呈现出各种明显不同类型的异常，具体取决于温度变化率和历史，但是，这些异常可以在与 FE 和 AFE 相共存区域中的 Pbam↔R3m 转变和倾斜 R3c↔R3m 转变的两个分量相对应的阶梯异常中得到很好的再现。
The phase transformations of ceramic PbZr1−xTixO3 are studied at the composition x=0.05 close to the morphotropic phase boundary between antiferroelectric orthorhombic Pbam and ferroelectric rhombohedral phases by elastic, dielectric, and x-ray diffraction measurements. Temperature scans at different rates show that the kinetics of the transition from R3m to Pbam is very sluggish, and is actually split into a slower polar component, appearing in the dielectric susceptibility and a nonpolar component, visible as a sharp stiffening of the Young's modulus. The latter is assigned to the establishment of the oxygen octahedral tilt pattern of the Pbam phase, and occurs at once at a temperature that decreases with increasing cooling rate. On heating, the transition occurs at a temperature 65 K higher than on quasistatic cooling, so that both components occur with a faster rate almost together. The Young's modulus presents a variety of apparently different types of anomalies, depending on temperature rate and history, which, however, can be well reproduced in terms of steplike anomalies corresponding to the two components of the Pbam↔R3m transition and the tilt R3c↔R3m transition in the region of coexistence of the FE and AFE phases.