Direct observation of intermediate twinning in the phase transformations of ferroelectric potassium sodium niobate
Direct observation of intermediate twinning in the phase transformations of ferroelectric potassium sodium niobate
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DOI：
10.1016/j.ceramint.2021.04.067
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发表时间：
2021-04
影响因子：
5.2
通讯作者：
P. Pop-Ghe;Monika Amundsen;C. Zamponi;A. Gunnæs;E. Quandt
中科院分区：
文献类型：
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作者：
P. Pop-Ghe;Monika Amundsen;C. Zamponi;A. Gunnæs;E. Quandt
本文采用变温X射线衍射和透射电子显微镜相结合的方法研究了铁电体K0·5Na0·5NbO3的一级相变机制。由此，在块体材料中抑制了异常晶粒生长，因为这是已知的由于引入的不均匀性而抑制测量再现性的特征。结果表明，该陶瓷的相变是多步过程，其特点是一个中间孪生阶段。由于钙钛矿型陶瓷可以被看作是关于位移转变的模型系统，所提出的实验给出了洞察陶瓷材料中的成核，传播路径和孪生机制。
In this study, temperature-dependent X-ray diffraction and transmission electron microscopy have been combined to reveal the mechanisms in the first-order phase transitions of ferroelectric K0·5Na0·5NbO3. Hereby, abnormal grain growth has been suppressed in the bulk material since it is a feature known to inhibit measurement reproducibility due to the introduced inhomogeneities. It is shown that phase transitions in this ceramic are multi-step processes, which feature an intermediate twinning stage. As perovskite-type ceramics can be regarded as model systems with respect to displacive transformations, the presented experiments give an insight into nucleation, propagation path and twinning mechanisms in ceramic materials.