论文部分内容阅读
为了考察Nb–Si–N纳米复合薄膜中的界面结构形式,采用基于密度泛函理论(DFT)的第一性原理方法,计算了单个Si原子在NbN晶体中固溶结构形式,以及Nb–Si–N中由Si原子形成的界面结构形式,并分别考察NbN、Nb–Si–N固溶结构及其界面结构形式的力学性能。计算结果表明:单个Si原子在NbN晶体中可以实现间隙固溶或置换固溶;Nb–Si–N中存在置换型界面与间隙型界面两类结构形式;Nb–Si–N固溶结构及其界面结构形式的弹性常数、体模量和剪切模量均低于NbN晶体的力学性能;较NbN的弹性模量各向异性有明显差异不同,置换型与间隙型界面的弹性模量各向异性并不十分突出,但是置换型与间隙型界面的弹性模量的最大值下降非常明显。
In order to investigate the interface structure of Nb-Si-N nanocomposite films, the first-principle method based on density functional theory (DFT) was used to calculate the solute structure of single Si atom in NbN crystal and the structure of Nb-Si -N by Si atoms, and the mechanical properties of NbN, Nb-Si-N solid solution structures and their interfacial structure were investigated respectively. The calculated results show that a single Si atom can form interstitial solution or substitutional solution in a NbN crystal. There are two types of structures in the Nb-Si-N interface: a substitutional interface and a gap-type interface. The Nb-Si-N solid solution structure and its The elastic constants, bulk modulus and shear modulus of the interfacial structure are lower than that of the NbN crystal. The elastic modulus anisotropy of NbN is obviously different. The opposite sex is not very prominent, but the maximum value of the elastic modulus of the displacement type and the gap type interface is obviously decreased.