纳米薄膜晶粒生长的厚度效应

Thickness Effect on Grain Growth in Nanocrystalline Films

应用各向异性蒙特卡罗方法模拟不同厚度纳米薄膜退火时的晶粒生长过程，通过引入厚度因子来修正Burke提出的动力学模型．结果表明：厚度效应对晶粒生长的抑制作用并非表现在晶粒生长初期，而是当晶粒尺寸达到薄膜厚度的0．8～1．2倍时才变得明显；修正后的抑制晶粒生长动力学方程可清晰描述纳米薄膜中的厚度效应，且与模拟结果更吻合．

Various stagnation effects of grain growth in nanocrystalline materials have been found, but thickness effect is hardly investigated, This paper presented an anisotropic Monte Carlo （MC） algorism to stimulate grain growth in nano-films with different thicknesses in annealing process. The simulation results reveal that thickness effect begins to be exhibited only when the average grain size reaches 0.8 to 1.2 times of the thickness of the films, not in the whole process of grain growth. Through introducing thickness factor, the paper modified Burke＇s grain growth kinetic model and obtained a new equation in better accordance with the simulation results as well as the physical model of thickness effect.