Atomistic mechanisms of nonstoichiometry-induced twin boundary structural transformation in titanium dioxide.
Atomistic mechanisms of nonstoichiometry-induced twin boundary structural transformation in titanium dioxide.
复制标题
DOI：
10.1038/ncomms8120
复制
发表时间：
2015-05-11
影响因子：
16.6
通讯作者：
Ikuhara, Yuichi
中科院分区：
文献类型：
--
作者：
Sun, Rong;Wang, Zhongchang;Saito, Mitsuhiro;Shibata, Naoya;Ikuhara, Yuichi
晶界（GB）相变经常发生在多晶材料中，当暴露于外部刺激时，并且普遍涉及对其性能的重大影响，但关于相变过程的原子尺度知识还远未开发出来。特别是，由于处理而装载缺陷的 GB 是否仍然可以传统上被认为是具有动力学捕获结构或旋转有序的无序区域，这是有争议的。在这里，我们结合先进的电子显微镜、光谱学和第一性原理计算来探测不同气氛下的单个TiO2晶界，并证明受激结构缺陷可以在晶界上自组装，形成有序结构，从而导致晶界非化学计量和原子尺度的结构转变。这种结构转变伴随着GB处的电子跃迁。三维变换为研究 GB 的结构缺陷以及制定操纵实际重要的 GB 变换的策略提供了新的视角。 多晶材料中的晶界强烈影响其机械性能。在这里，作者通过高分辨率电子显微镜研究了多晶 TiO2，并观察到结构缺陷在晶界处形成有序结构，影响其性能。
Grain boundary (GB) phase transformations often occur in polycrystalline materials while exposed to external stimuli and are universally implicated in substantially affecting their properties, yet atomic-scale knowledge on the transformation process is far from developed. In particular, whether GBs loaded with defects due to treatments can still be conventionally considered as disordered areas with kinetically trapped structure or turn ordered is debated. Here we combine advanced electron microscopy, spectroscopy and first-principles calculations to probe individual TiO2 GB subject to different atmosphere, and to demonstrate that stimulated structural defects can self-assemble at GB, forming an ordered structure, which results in GB nonstoichiometry and structural transformations at the atomic scale. Such structural transformation is accompanied with electronic transition at GB. The three-dimensional transformations afford new perspectives on the structural defects at GBs and on the development of strategies to manipulate practically significant GB transformations. Grain boundaries in polycrystalline materials strongly influence their mechanical properties. Here, the authors investigate polycrystalline TiO2 by high-resolution electron microscopy and observe that structural defects form ordered structures at grain boundaries influencing their properties.
登录
查看更多内容
Fe3O4 中高稳定反相边界缺陷的原子尺度结构和性质
影响因子：
16.6
作者：
McKenna, Keith P.;Hofer, Florian;Gilks, Daniel;Lazarov, Vlado K.;Chen, Chunlin;Wang, Zhongchang;Ikuhara, Yuichi
通讯作者：
Ikuhara, Yuichi
影响因子：
2.2
作者：
Findlay, S. D.;Shibata, N.;Ikuhara, Y.
通讯作者：
Ikuhara, Y.
影响因子：
8.6
作者：
Abou-Ras, Daniel;Schaffer, Bernhard;Unold, Thomas
通讯作者：
Unold, Thomas
影响因子：
3.7
作者：
Koerner, Wolfgang;Elsaesser, Christian
通讯作者：
Elsaesser, Christian
DOI：
10.1093/jmicro/dfr049
发表时间：
2011-08-01
期刊：
JOURNAL OF ELECTRON MICROSCOPY
影响因子：
--
作者：
Ikuhara, Yuichi
通讯作者：
Ikuhara, Yuichi