Aguirre Rodolfo, Abdullah Sharmin, Zhou Xiaowang, Zubia David
Department of Electrical and Computer Engineering, University of Texas at El Paso, El Paso, TX 79968, USA.
Mechanics of Materials Department, Sandia National Laboratories, Livermore, CA 94550, USA.
Nanomaterials (Basel). 2019 Apr 4;9(4):552. doi: 10.3390/nano9040552.
Molecular dynamics (MD) simulations have been applied to study mobilities of Σ3, Σ7 and Σ11 grain boundaries in CdTe. First, an existing MD approach to drive the motion of grain boundaries in face-centered-cubic and body-centered-cubic crystals was generalized for arbitrary crystals. MD simulations were next performed to calculate grain boundary velocities in CdTe crystals at different temperatures, driving forces, and grain boundary terminations. Here a grain boundary is said to be Te-terminated if its migration encounters sequentially C d · T e - C d · T e … planes, where "·" and "-" represent short and long spacing respectively. Likewise, a grain boundary is said to be Cd-terminated if its migration encounters sequentially T e · C d - T e · C d … planes. Grain boundary mobility laws, suitable for engineering time and length scales, were then obtained by fitting the MD results to Arrhenius equation. These studies indicated that the Σ3 grain boundary has significantly lower mobility than the Σ7 and Σ11 grain boundaries. The Σ7 Te-terminated grain boundary has lower mobility than the Σ7 Cd-terminated grain boundary, and that the Σ11 Cd-terminated grain boundary has lower mobility than the Σ11 Te-terminated grain boundary.
分子动力学（MD）模拟已被用于研究碲化镉中Σ3、Σ7和Σ11晶界的迁移率。首先，将一种现有的用于驱动面心立方和体心立方晶体中晶界运动的MD方法推广到任意晶体。接下来进行MD模拟，以计算碲化镉晶体在不同温度、驱动力和晶界终端条件下的晶界速度。这里，如果晶界迁移依次遇到Cd·Te - Cd·Te…平面（其中“·”和“-”分别表示短间距和长间距），则称该晶界为Te端接。同样，如果晶界迁移依次遇到Te·Cd - Te·Cd…平面，则称该晶界为Cd端接。然后，通过将MD结果拟合到阿伦尼乌斯方程，获得了适用于工程时间和长度尺度的晶界迁移率定律。这些研究表明，Σ3晶界的迁移率明显低于Σ7和Σ11晶界。Σ7的Te端接晶界的迁移率低于Σ7的Cd端接晶界，且Σ11的Cd端接晶界的迁移率低于Σ11的Te端接晶界。
