Chemisorption on magnetic cobalt systems

Adsorption of oxygen and carbon monoxide on several ferromagnetic cobalt sy stems is studied theoretically. The method is based on a self-consistent ti ght-binding recursion-scheme treatment and adsorption on the semi-infinite Co(0 0 0 1 ) crystal and several small Co clusters is considered. It is fou nd that atomic oxygen has only moderate effect on the cobalt magnetization. On the Co (0 0 0 1) surface, the magnetization is strongly suppressed by C O in the atop position but not at the bridge chemisorption site. At cluster s, CO at atop geometry is also a good magnetization killer. (C) 1999 Elsevi er Science B.V. All rights reserved.