第一性原理计算fcc-Nb_(1-x)Si_xN的调幅分解  

Study on Spinodal Decomposition of fcc-Nb_(1-x)Si_xN by First Principles

作　　者：牛建钢[1] 丁振君[1] 高巍[1] 谢飞[1] 田晓[1] 

机构地区：[1]河北大学质量技术监督学院,保定071001

出　　处：《材料导报》2010年第14期78-80,共3页Materials Reports

基　　金：河北省教育厅科研计划项目(z2008304);河北省教育厅科学研究项目(z2009308)

摘　　要：通过第一性原理计算方法计算了三元固溶体fcc-Nb1-xSixN的总能,在此基础上计算了其分离能和调幅分解线。结果表明,fcc-Nb1-xSixN是亚稳相,能经调幅分解机制分解为fcc-NbN和fcc-SiN。组元相形成的应变能小于分离能,不会抑制fcc-Nb1-xSixN的共格调幅分解。fcc-Nb1-xSixN的Si含量为渗透阈值时不会发生调幅分解。fcc-SiN可能较快转变为β-Si3N4,从而抑制fcc-Nb1-xSixN的共格调幅分解。Total energies of ternary solution fcc-Nb1-xSirN phase are calculated by first principle method, and de-mixing energy and spinodal curve of fcc-Nb1-x SirN phase are calculated. The results show thatfcc-Nb1-xSirN is metastable and can be decomposed to fcc-NbN and fcc-SiN via spinodal decomposition. The strain energy between the constituent phases is smaller than the de-mixing energy, which can＇t hinder the spinodal decomposition. Spinodal decomposition can not proceed for Si composition of fcc-Nb1-xSirN identical to the percolation threshold. The coherent spinodal decomposition may probably be hindered due to rapid phase transformation from fcc-SiN to β-Si3N4.

关 键 词：超硬薄膜 氮化物 调幅分解 第一性原理 

分 类 号：TB383[一般工业技术—材料科学与工程]