β-Si3N4转变为β-C3N4的最可能路径以及两者弹性、硬度的对比研究  

The Most Probable Path of β-Si3N4Transforming to β-C3N4 and the Comparison of Their Elasticity and Hardness

作　　者：黄宇 袁婷婷 陈志谦 

机构地区：[1]西南大学材料与能源学部,重庆

出　　处：《材料科学》2017年第3期266-274,共9页Material Sciences

基　　金：国家自然科学基金资助(批准号:51601153)。

摘　　要：本文基于密度泛函理论的第一性原理,运用平面波超软赝势和广义梯度近似(GGA)势场计算了C原子替换β-Si3N4中Si原子过程中各结构的体系能量,以此来寻找β-Si3N4转变为β-C3N4的最可能路径。另外计算和对比了β-Si3N4和β-C3N4的弹性和硬度。结果显示,β-C3N4的弹性模量E、体弹模量B、剪切模量G和硬度都比β-Si3N4大,原因在于β-C3N4中的C-N键比β-Si3N4中的Si-N键强度更高,因此β-C3N4原子间的结合力更大。β-C3N4良好的稳定性以及优异的力学性能决定了其将具有广泛的应用。Based on the first-principles of density functional theory with plane wave ultrasoft pseudopotential method and the generalized gradient approximation (GGA) potential field, we calculated the system energy of each structure in the process of replacing the Si atoms in β-Si3N4 structure with C atoms in order to find the most likely path of β-Si3N4 converting into β-C3N4. The elasticity and hardness of β-Si3N4 and β-C3N4 were also calculated and compared. The results show that the elastic modulus E, bulk modulus B, shear modulus G and hardness of β-C3N4 are larger than that of β-Si3N4. The reason is that the strength of the C-N bond in β-C3N4 is higher than the strength of the Si-N bond in β-Si3N4, as a result, the binding force between β-C3N4 atoms is greater. The excellent stability and mechanical properties of β-C3N4 determine a wide range of its applications.

关 键 词：第一性原理 转变路径 弹性 硬度 

分 类 号：G6[文化科学—教育学]