First-principles methods were employed to investigate the adsorption and diffusion of Co on Si(001). After determining the surface and subsurface binding sites, the nudged elastic band calculations were performed to explore the surface diffusion and the inward diffusion from the surface into the subsurface for Co on Si(001). It was found that Co atoms diffuse quickly to the subsurface from the surface, while the surface diffusion was slower. At low coverage, the calculations predicted that Co atoms will be mainly found underneath the surface Si layer, which was in agreement with experimental results. The diffusion coefficients for Co diffusion into the subsurface were also calculated and compared with experimental results.

Adsorption and Diffusion of Co on the Si(001) Surface. G.W.Peng, A.C.H.Huan, E.S.Tok, Y.P.Feng: Physical Review B, 2006, 74[19], 195335 (5pp)