第一性原理计算TiN(111)/BN/TiN(111)界面的电子结构、成键特性和结合强度

利用第一性原理计算方法研究了TiN(111)/BN/TiN(111)界面的16个理论界面构型.计算结果表明,最稳定界面构型为top-top-BN构型,此构型中B原子只与周围N原子成键,为四面体配位.同时计算了top-top-BN构型的电子结构和成键特性以及界面结合强度,结果表明,top-top-BN构型界面上的键为较强共价键,其界面结合强度比TiN(111)板层或TiN块体材料的(111)晶面间的结合强度大,说明此构型具有强界面特征.

FIRST-PRINCIPLES CALCULATION OF ELECTRONIC STRUCTURE,BONDING CHARACTERISTIC AND BONDING STRENGTH OF TiN(111)/BN/TiN(111) INTERFACE

The nanocomposite 'nc-TiN/a-BN' as a representation of the family of super-hard nitride-based nanocomposites, which is a nanocomposite thin film material, exhibits a significant hardness enhancement as compared with the pure constituents. In this paper, first-principles calcula-tions were performed to investigate the role of interfaces in the nanocomposite 'nc-TiN/a-BN' , to which less attention has been paid up to now. In order to determine theoretically the stable interface configuration in 'nc-TiN/a-BN' , 16 possible theoretical TiN(111)/BN/TiN(111) sandwich interface configurations have been constructed based on the structure characteristic of 'nc-TiN/a-BN' . It is found in this calculation that the most favorable interface configuration is 'top-top-BN' , which is closely related to each B atom covalently bonding to its tetrahedrally coordinated N atoms in it. Its electronic structure is calculated. The calculated results show that the bonds at the interface in 'top-top-BN' configuration are covalent. Its interface bonding strength is higher than that between two 111 crystalline planes in slab TiN or bulk TiN.