A molecular dynamics simulation of self-diffusion on Fe surfaces

作者：Wang, Changqing^*; Qin, Zhen; Zhang, Yongsheng; Sun, Qiang; Jia, Yu

来源：Applied Surface Science, 2012, 258(10): 4294-4300.

DOI：10.1016/j.apsusc.2011.12.084

• EAM potential
• Molecular dynamics
• Diffusion
• Nudged elastic band (NEB) method
• Iron
• Adsorption
• Vacancy

Using embedded-atom-method (EAM) potential, an adatom and a vacancy diffusion processes have been simulated in detail by molecular dynamics on three Fe surfaces, Fe ( 1 1 0), Fe ( 1 0 0), and Fe ( 1 1 1). Our results reveal that adatom adsorption energies and diffusion migration energies on these surfaces have similar monotonic trend to the relative layer spacing relaxation, R-(110) <R-(100) <R-(111), adsorption energy, E-a(110)(a) < E-a(100)(a) < E-a(111)(a), diffusion migration energy, E-a(110)(m) < E-a(100)(m) < E-a(111)(m). However, for a vacancy, formation and migration energies have a different trend, formation energy, E-v(111)(f) < E-v(100)(f) < E-v(110)(f), migration energy, E-v(111)(m) < E-v(110)(m) < E-v(100)(m). On the Fe (1 1 0) surface, simple jumping of an adatom (or a vacancy) is the main diffusion mechanism with relatively low migration energy barrier; nevertheless, exchange with a surface atom plays a dominant role in surface diffusion on the Fe (1 0 0) and Fe (1 1 1) surfaces.

• 出版日期2012-3-1
• 单位郑州大学; 华北水利水电大学; 洛阳理工学院