温度对硅纳米薄膜杨氏模量的影响

Effect of Temperature on the Young's Modulus of Silicon Nano-Films

采用分子动力学方法计算了100K、300K、400K和500K四个温度下硅纳米薄膜[110]与[110]两个方向上的杨氏模量.结果表明,[110]与[110]两个方向杨氏模量有较大差别,约为25GPa;[110]与[110]的杨氏模量随温度变化的斜率几乎一样,为-0.007Gpa/K.研究还表明,[110]与[110]两个方向具有几乎相等的热膨胀系数,量级在10-6/K.

At different temperature(100 K、300 K、400 K、500 K),molecular dynamics(MD)simulations are used to study the Young's modulis along[110]and[1^-10]directions of silicon nano-films with reconstructed{100}surfaces.The results show that there is a difference of 25 GPa between these two Young's modulis.And the variation ratio of the Young's modulus to the temperature is nearly equal.At the same time,the results also show that the coefficients of thermal expansion along these two directions have nearly the same value.