Effect of S adsorption on magnetic Co(0001) surface: a DFT study S. H. Ma, X. T. Zu, Z. Y. Jiao and H. Y. Xiao Eur. Phys. J. B, 61 3 (2008) 319-324 Published online: 29 February 2008 DOI: 10.1140/epjb/e2008-00086-0