Multistep coupling of preexisting local ferroic distortions in PbTiO3 above the Curie temperature
Multistep coupling of preexisting local ferroic distortions in PbTiO3 above the Curie temperature
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DOI：
10.1088/1361-648x/aae344
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
I. Margaritescu;K. Datta;B. Mihailova
中科院分区：
文献类型：
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作者：
I. Margaritescu;K. Datta;B. Mihailova
在130-1040 K的温度范围内对主要的铁电体PbTiO 3进行了温度相关的拉曼光谱分析，特别关注其居里温度K以上的顺电态。的异常拉曼散射的温度演化表明，不仅本地铁电畸变坚持在温度远高于，但也有一个序列的不同的耦合过程之前的远程铁电秩序的外观。我们的研究结果表明，类似于弛豫铁电体，顺电相的PbTiO 3可以被认为是一个遍历系统的局部铁性扭曲，这似乎只有平均立方对称。
Temperature-dependent Raman spectroscopic analyses were performed for the prominent ferroelectric PbTiO3 in the temperature range 130–1040 K, focusing particularly on its paraelectric state above the Curie temperature K. The temperature evolution of the anomalous Raman scattering reveals that not only local ferroic distortions persist at temperatures well above , but also there is a sequence of different coupling processes preceding the appearance of long-range ferroelectric order at . Our results indicate that, similar to relaxor ferroelectrics, the paraelectric phase of PbTiO3 can be considered as an ergodic system of local ferroic distortions, which only on average appears to have cubic symmetry.