Nanocluster rotation on Pt surfaces: Twist boundaries
Nanocluster rotation on Pt surfaces: Twist boundaries
复制标题
DOI：
10.1103/physrevb.64.205409
复制
发表时间：
2001-10
影响因子：
3.7
通讯作者：
Y. Ashkenazy;R. Averback;K. Albe
中科院分区：
文献类型：
--
作者：
Y. Ashkenazy;R. Averback;K. Albe
采用分子动力学模拟方法研究了纳米级Pt粒子在Pt表面的分布。结果表明，对于低折射率平面对称扭转边界的简单情况，系统的结构和动力学对有限尺寸效应敏感。也就是说，在特定的纳米颗粒尺寸以下，颗粒将自身与衬底对准，而对于较大的颗粒，产生稳定的晶界位错阵列。结果表明，纳米颗粒的旋转是在颗粒-衬底界面处产生的晶界位错的非热滑移的直接结果。尺寸效应是纳米级颗粒所特有的，因此在过去的实验中尚未观察到。模拟还表明，边界的能量和结构也受到系统大小的影响。
Nanoscale Pt particles situated on a Pt surface are studied by molecular dynamics simulations. It is shown that for the simple case of symmetrical twist boundaries with low index planes, the structure and dynamics of the system are sensitive to finite size effects. Namely, below a specific nanoparticle size the particles will align themselves with the substrate, while for larger particles a stable array of grain boundary dislocations is created. It is shown that nanoparticle rotation is a direct result of athermal slip of the grain boundary dislocations that are created at the particle-substrate interface. The size effects are unique to nano-sized particles and thus have not yet been observed in past experiments. The simulations also show that the energy and structure of the boundaries are also affected by the system size.