Influence of the substrate on the magnetic anisotropy of monatomic nanowires

The magnetic anisotropy energy of Fe and Co monatomic nanowires both freestanding and at the step edge of a Pt surface is investigated within the framework of the density-functional theory and local-spin-density approximation. Various types of analysis of the calculated data reveal that the spin-orbit interaction of the Pt atoms and the hybridization between the electronic states have an important impact on the direction of the easy axis and on the magnitude of the magnetic anisotropy, both by a direct contribution localized at the Pt atoms and by an indirect contribution due to the modification of the Co-localized part via hybridization effects.