Abstract The interfacial microstructure and defects formed during the growth of anatase TiO2 nanocrystalline by oriented attachment (OA) in the process of hydrothermal synthesis have been studied by using high-resolution transmission electron microscope (HRTEM) combined with theoretical simulation. In the {1 0 1} crystal plane of anatase TiO2 nanoparticles, it is easy to observe that the nanocrystal grains are attached to form large single crystals or twin structure through high resolution energy filtered images. At the initial stage of synthesis, obvious changes of interplanar spacing between crystal planes, lattice distortions or dislocations could be observed at the interfaces of those unstable grains. The analyses on the Burgers vector loop of dislocations conclude that the Burgers vectors are 1/2〈1 0 1〉. Furthermore, the simulated images and the atomic structure models based on the captured images are in perfect agreement with the original ones. Meanwhile, the OA of anatase TiO2 nanoparticles on {1 1 2} crystal plane is also observed and twin crystals are formed along 〈3 1 1〉 crystallographic zone axis including dislocations at the interfaces. However, due to the damages of electron irradiation, few high-resolution images of these grains have been obtained. Analysis of these interfacial structures provide a new idea to understand the formation and transformation of the microstructure of anatase TiO2 nanoparticles during hydrothermal synthesis.

中文翻译：

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水热结构法研究锐钛矿型二氧化钛的界面晶格起源

摘要 采用高分辨率透射电子显微镜（HRTEM）结合理论模拟，研究了水热合成过程中定向附着（OA）在锐钛矿型TiO2纳米晶生长过程中形成的界面微观结构和缺陷。在锐钛矿TiO2纳米颗粒的{1 0 1}晶面，通过高分辨率能量过滤图像很容易观察到纳米晶粒附着形成大的单晶或孪晶结构。在合成的初始阶段，在这些不稳定晶粒的界面处可以观察到晶面之间的晶面间距、晶格畸变或位错的明显变化。对位错的 Burgers 向量环的分析得出结论，Burgers 向量为 1/2〈1 0 1〉。此外，模拟图像和基于捕获图像的原子结构模型与原始图像完全吻合。同时，还观察到锐钛矿TiO2纳米颗粒在{1 1 2}晶面上的OA，并且沿<3 1 1>晶区轴形成了孪晶，包括界面处的位错。然而，由于电子辐照的损伤，这些晶粒的高分辨率图像很少获得。对这些界面结构的分析为理解水热合成过程中锐钛矿 TiO2 纳米粒子微观结构的形成和转变提供了新的思路。还观察到锐钛矿 TiO2 纳米粒子在 {1 1 2} 晶面上的 OA，并且沿〈3 1 1〉晶区轴形成双晶，包括界面处的位错。然而，由于电子辐照的破坏，这些晶粒的高分辨率图像很少获得。对这些界面结构的分析为理解水热合成过程中锐钛矿 TiO2 纳米粒子微观结构的形成和转变提供了新的思路。还观察到锐钛矿 TiO2 纳米粒子在 {1 1 2} 晶面上的 OA，并且沿〈3 1 1〉晶区轴形成双晶，包括界面处的位错。然而，由于电子辐照的破坏，这些晶粒的高分辨率图像很少获得。对这些界面结构的分析为理解水热合成过程中锐钛矿 TiO2 纳米粒子微观结构的形成和转变提供了新的思路。