Adsorption characteristics of atomic nitrogen on ruthenium surfaces

We have studied the adsorption, vibration, and diffusion of N atoms on Ru(0001), (101¯0), (112¯0) and (112¯1) surfaces by means of the 5-parameter Morse potential (5-MP) of interaction between atomic nitrogen and a metal surface. The adsorption sites, adsorption geometry, binding energy and eigenvibration of atomic nitrogen on the different ruthenium surfaces are calculated. It is shown that atomic nitrogen always preferably occupies the high coordination sites on Ru surfaces. The 4-fold site is the preferable adsorption site for atomic nitrogen on both open Ru(112¯0) and (112¯1) surfaces while 3-fold site is the most stable adsorption site for atomic nitrogen on both Ru(0001) and (101¯0) surfaces. Moreover, we find the lowest energy pathway of diffusion and diffusion barriers of atomic nitrogen on the surfaces.