Anisotropy Enhancement in Co Granular Multilayers by Capping

摘要

The effect of capping with Cu, Au and Pt of an array of Co nanoparticles is revised. The magnetic surface anisotropy K_S was found to be the dominant contribution to the effective anisotropy K_(eff) of the particles. Recent X-ray Magnetic Circular Dichroism (XMCD) measurements show that there is hybridization between the 3d Co electrons and the d and 4p electrons of the capping metal. By comparison to the mechanisms which give rise to the surface anisotropy in thin films, it is argued that this hybridization governs the modification of K_S, and hence, of K_(eff).