面心立方铁纳米粒子的相变与并合行为的分子动力学研究

Phase transition and coalescence behavior of fcc Fe nanoparticles: a molecular dynamics study

本文采用分子动力学模拟结合Finnis-Sinclair多体势研究了面心立方铁纳米粒子在加温过程中的相变与并合行为.模拟结果表明:纳米粒子在熔化之前均发生了由面心立方至体心立方的马氏体相变;大小相等的两纳米粒子在并合之前发生了相对转动;而大小不等的两纳米粒子在并合过程中并未出现转动,小纳米粒子倾向于吸附在大纳米粒子上,并随着温度的升高而熔化,最终形成更大的纳米粒子.

In this paper, we present a systematic investigation on phase transition and coalescence behavior of fcc Fe nanoparticles under heating by molecular dynamics approach with Finnis-Sinclair many-body potential. The simulation results show that for fcc Fe nanoparticles, the martensitic transformation from fcc to bcc phase occurs prior to the melting. Relative rotation occurs between two like nanoparticles, but it does not happen in two nanoparticles with different sizes. A small nanoparticle prfers to adhere to a large one and is melted with temperature increasing, resulting in the final formation of a larger particle.