Density-functional study of adsorption of Co on Si(100)

We have studied the stable sites for Co both on the surface of Si(100) and subsurface by using ab initio methods. We show that the most stable surface site for Co is situated in the dimer trenches (the low site). The subsurface sites that we study are all found to be more stable than the most stable surface site. The most stable subsurface site is the under-dimer site. The most stable site of all is, however, the dimer vacancy site formed by removing the dimer above the cobalt in the under-dimer site.