Microscopic View of Nucleation in the Anatase-to-Rutile Transformation
Microscopic View of Nucleation in the Anatase-to-Rutile Transformation
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DOI：
10.1021/jp301228x
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发表时间：
2012-04
影响因子：
3.7
通讯作者：
Ya Zhou;K. Fichthorn
中科院分区：
文献类型：
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作者：
Ya Zhou;K. Fichthorn
我们使用分子模拟技术来研究锐钛矿到金红石的转变在二氧化钛纳米晶体。热力学分析表明，边缘和角落原子显着影响的临界尺寸，金红石纳米晶体成为积极的首选超过铈。我们使用分子动力学模拟探测动力学的转换，在个别的纳米晶体，以及在纳米聚集体。我们使用模拟X射线衍射跟踪结构演化。此外，我们开发了一个局部序参数来区分个别钛离子的金红石，金红石，或双{112}孪晶。我们应用我们的局部序参量来跟踪金红石晶核的形成和生长。锐钛矿型{112}孪晶易形成于团聚体的表面和界面，并观察到在孪晶间有金红石形成。稳定的金红石核在生长期间保持{101}晶面，这是交替的双{112}孪晶层成核的结果。我们的结果是一致的...
We use molecular simulation techniques to investigate the anatase-to-rutile transformation in TiO2 nanocrystals. A thermodynamic analysis indicates that edge and corner atoms significantly influence the critical size at which rutile nanocrystals become energetically preferred over anatase. We use molecular dynamics simulations to probe kinetics of the transformation in individual anatase nanocrystals as well as in nanocrystal aggregates. We follow structural evolution using simulated X-ray diffraction. Additionally, we develop a local order parameter to distinguish individual Ti ions as anatase, rutile, or anatase {112} twin-like. We apply our local order parameter to track the formation and growth of rutile nuclei. Anatase {112} twins form easily at surfaces and interfaces of nanocrystal aggregates, and we observe that rutile forms among the twins. Stable rutile nuclei maintain {101} facets during growth as a result of nucleation from layers of alternating anatase {112} twins. Our results are in agreemen...