Koura A, Shimojo F
Department of Physics, Kumamoto University, Kumamoto, Japan.
J Phys Condens Matter. 2020 Jun 3;32(24):244001. doi: 10.1088/1361-648X/ab7b1b.
We have investigated the intermediate range structure of amorphous CuGeTe based on ab initio molecular dynamics simulations. The highest population of ring size is three, which makes the triangle structure. This ring consists of mainly CuTe. Rings may also consist of CuCuCu, CuGe, and CuGeTe, where approximately 88% of Cu atoms in the system are related with the three-membered ring. The second highest population of ring size is five. Three- and five-membered rings in the amorphous phase originate from six-membered ring in the crystalline phase. This situation can enhance the phase transition between crystalline and amorphous phases. In the phase change process, Cu atoms may diffuse in the amorphous state with changing bonds. The diffusion coefficient of Cu D is estimated to be approximately 0.12 × 10 m s. Such high diffusion coefficient of Cu atoms is contributed from only 10% of Cu atoms in the amorphous phase.
我们基于从头算分子动力学模拟研究了非晶态CuGeTe的中程结构。环尺寸的最大占比是三，形成了三角形结构。这个环主要由CuTe组成。环也可能由CuCuCu、CuGe和CuGeTe组成，系统中约88%的Cu原子与三元环有关。环尺寸的第二大占比是五。非晶相中的三元环和五元环起源于晶相中的六元环。这种情况可以增强晶相和非晶相之间的相变。在相变过程中，Cu原子可能在非晶态下随着键的变化而扩散。Cu的扩散系数D估计约为0.12×10 m²/s。Cu原子如此高的扩散系数仅由非晶相中10%的Cu原子贡献。
