金刚石类超薄膜的力学性能和表面性质与掺杂剂对它的影响

Mechanical Properties of Ultrathin Diamond-like Films and the Effects of Surfaces and Dopants

用经典的力场方法对金刚石(C)、氮化硼(BNx)和氮化碳(CNx)结晶硬涂层膜的力学性能进行了探讨,确定原子结构、本体和杨氏模量为膜厚度的函数。探讨了吸附物对金刚石模量或表面张力的影响。另外,研究了不同氮化物中氮浓度以及不同取向和键合环境(sp2和sp3)下氮原子对模量的影响,揭示了系统的规律。同时,测定了空位对硬度的影响。

Mechanical properties were evaluated for crystalline hard coating materials including diamond （C）, boron nitride （BNx）, and carbon nitride （CNx） films with a classical force field method. The atomic structures, the bulk and Young＇s moduli were determined as a function of film thickness ranging from 1 to 10 nm. The effects of adsorbate on moduli and surface stress of the diamond thin films were investigated. In addition, the effects of nitrogen concentration and nitrogen in different coordination and bonding environment （sp^2 and sp^3） on moduli were studied for boron nitride and carbon nitride materials. Systematic and interesting trends were revealed. Finally the effect of vacancies on hardness was also examined.