arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1709.04871cond-mat.mtrl-scicond-mat.other
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Na0.5Bi 0.5TiO_3-压电陶瓷中局域无序的三维电子漫散射研究

Local disorder in Na0.5Bi0.5TiO3-piezoceramic determined by 3D electron diffuse scattering

Alexandra Neagu, Cheuk-Wai Tai

摘要:

在Na0.5Bi0.5TiO3基固溶体的局部结构扭曲已被证明发挥了至关重要的作用,在理解和调整其增强的压电性能附近的准同型相界。本文利用三维电子衍射技术,在倒易空间中对85%Na_(0.5)Bi_(0.5)TiO_3 - 10%Bi_(0.5)K_(0.5)TiO_3 - 5%BaTiO_3无铅三元系的所有局域结构无序进行了定位。此外,通过分析所观察到的弱漫散射的强度和形态,开发了一个全面的局部无序模型。我们发现,所研究的陶瓷由片状同相氧八面体纳米畴随机分布在反相倾斜矩阵。此外,A位化学短程秩序的Na/Bi和极性位移有助于不同种类的漫散射。该模型解释了所有观察到的衍射特征,并提供了深入了解持续的争议在Na0.5Bi0.5TiO3基固溶体的局部结构扭曲的性质。

英文摘要:

Local structural distortions in Na0.5Bi0.5TiO3-based solid solutions have been proved to play a crucial role in understanding and tuning their enhanced piezoelectric properties near the morphotropic phase boundary. In this work all local structural disorders in a lead-free ternary system, namely 85%Na0.5Bi0.5TiO3-10%Bi0.5K0.5TiO3-5%BaTiO3, were mapped in reciprocal space by 3D electron diffraction. Furthermore, a comprehensive model of the local disorder was developed by analysing the intensity and morphology of the observed weak diffuse scattering. We found that the studied ceramics consists of plate-like in-phase oxygen octahedral nanoscale domains randomly distributed in an antiphase tilted matrix. In addition, A-site chemical short-range order of Na/Bi and polar displacements contribute to different kinds of diffuse scattering. The proposed model explains all the observed diffraction features and offers insight into the ongoing controversy over the nature of local structural distortions in Na0.5Bi0.5TiO3-based solid solutions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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