Xu Chao, Liu Futi, Liu Chunmei, Wang Pei, Liu Huaping
Faculty of Science, Yibin University, Yibin 644007, China.
Key Laboratory of Computational Physics, Yibin University, Yibin 644007, China.
Nanomaterials (Basel). 2021 Nov 10;11(11):3014. doi: 10.3390/nano11113014.
Although ZnSe has been widely studied due to its attractive electronic and optoelectronic properties, limited data on its plastic deformations are available. Through molecular dynamics simulations, we have investigated the indentations on the (001), (110), and (111) planes of ZnSe nano films. Our results indicate that the elastic modulus, incipient plasticity, elastic recovery ratio, and the structural evolutions during the indenting process of ZnSe nano films show obvious anisotropy. To analyze the correlation of structural evolution and mechanical responses, the atomic displacement vectors, atomic arrangements, and the dislocations of the indented samples are analyzed. Our simulations revealed that the plastic deformations of the indented ZnSe nano films are dominated by the nucleation and propagation of 1/2<110> type dislocations, and the symmetrically distributed prismatic loops emitted during the indenting process are closely related with the mechanical properties. By studying the evolutions of microstructures, the formation process of the dislocations, as well as the formation mechanisms of the emitted prismatic loops under the indented crystalline planes are discussed. The results presented in this work not only provide an answer for the questions about indentation responses of ZnSe nano films, but also offer insight into its plastic deformation mechanisms.
尽管ZnSe因其具有吸引力的电子和光电特性而受到广泛研究，但关于其塑性变形的数据有限。通过分子动力学模拟，我们研究了ZnSe纳米薄膜(001)、(110)和(111)平面上的压痕。我们的结果表明，ZnSe纳米薄膜在压痕过程中的弹性模量、初始塑性、弹性回复率和结构演变表现出明显的各向异性。为了分析结构演变与力学响应的相关性，对压痕样品的原子位移矢量、原子排列和位错进行了分析。我们的模拟表明，压痕ZnSe纳米薄膜的塑性变形主要由1/2<110>型位错的形核和扩展主导，压痕过程中发射的对称分布棱柱形位错环与力学性能密切相关。通过研究微观结构的演变，讨论了位错的形成过程以及在压痕晶面下发射的棱柱形位错环的形成机制。本文给出的结果不仅为ZnSe纳米薄膜压痕响应的问题提供了答案，也为其塑性变形机制提供了深入了解。
