Abstract:

AbstractThe 5-parameter Morse potential(5-MP) of the interaction between H atom and Fe surface was constructed. The absorption and diffusion of H on Fe low-index surface and Fe(211) high-index surface were investigated with 5-MP in detail. All the critical characteristics of the system were obtained, such as adsorption site, adsorption geometry, binding energy, eigenvalues for vibration, etc. And our calculated results are in good accordance with the experiments. The calculated results show that H atom is located at the fourfold hollow site of the intact Fe(100) surface, the vibrational frequency is 1 009 cm^-1; and on Fe(110) and Fe(211) surfaces, H atom trends to occupy quasi-3-fold site without exception, the vibrational frequencies are 1 054 and 1 046 cm^-1, respectively. However ,the most stable site on Fe(111) surface is bond site, the vibrational frequency is 1 030 cm^-1.

Key words: Keywords H-Fe surface system; 5-MP; Surface adsorption; Surface vibration; H-Fe(211) system