Magnetic nanostructures on the fcc Fe/Cn(100) surface

We present systematic ab initio calculations for the magnetic moments of 3d and 4d transition-metal impurities on the high-moment ferromagnetic phase of fee Fe/Cu(100) surface. We find that on this substrate the moments of th e impurities are in general larger than on bcc Fe. Furthermore the transiti on from antiferromagnetic to ferromagnetic coupling occurs at smaller valen cies. A very subtle behavior is found for Ru nanostructures, which show fer romagnetic coupling for adatoms and linear chains, but antiferromagnetic co upling for larger islands and monolayers.