Crystal Orientation Effect on the Subsurface Deformation of Monocrystalline Germanium in Nanometric Cutting.
Crystal Orientation Effect on the Subsurface Deformation of Monocrystalline Germanium in Nanometric Cutting.
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纳米切割中单晶锗亚表面变形的晶体取向效应
DOI：
10.1186/s11671-017-2047-3
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发表时间：
2017-12
影响因子：
--
通讯作者：
Fang F
中科院分区：
文献类型：
--
作者：
Lai M;Zhang X;Fang F
对单晶锗进行纳米切削的分子动力学模拟，以研究纳米切削过程中和切削后的亚表面变形。通过分子动力学模拟建立了非晶锗的连续无规网络模型，并提取其特征参数与加工变形层的特征参数进行比较。配位数分布和径向分布函数（RDF）表明加工表面呈现出类似的非晶态。分别对锗的（010）、（101）和（111）晶面进行纳米切削，研究了各向异性的亚表面变形。变形结构易于沿110滑移系延伸，这导致不同方向和晶面上变形层的形状和厚度存在差异。在加工表面上，亚表面变形层厚度越大，表面恢复高度越大。为了获得锗加工表面变形层的临界厚度极限，根据纳米切削与纳米压痕的相关性，对每个晶面提出了优化的切削方向。
Molecular dynamics simulations of nanometric cutting on monocrystalline germanium are conducted to investigate the subsurface deformation during and after nanometric cutting. The continuous random network model of amorphous germanium is established by molecular dynamics simulation, and its characteristic parameters are extracted to compare with those of the machined deformed layer. The coordination number distribution and radial distribution function (RDF) show that the machined surface presents the similar amorphous state. The anisotropic subsurface deformation is studied by nanometric cutting on the (010), (101), and (111) crystal planes of germanium, respectively. The deformed structures are prone to extend along the 110 slip system, which leads to the difference in the shape and thickness of the deformed layer on various directions and crystal planes. On machined surface, the greater thickness of subsurface deformed layer induces the greater surface recovery height. In order to get the critical thickness limit of deformed layer on machined surface of germanium, the optimized cutting direction on each crystal plane is suggested according to the relevance of the nanometric cutting to the nanoindentation.