Morphology and capping effects in the magnetic and magneto-optical properties of nanoparticulate Co films

Abstract

Magnetic and magneto-optical properties of Co films are studied as a function of the morphology and the capping layer. We show that the nanoparticulate structure of the Co films has a clear influence on the magnetic and magneto-optical properties of the system. Kerr measurements combined with x-ray magnetic circular dichroism provide evidence of a strong correlation between the collective magnetic behavior of the system and the individual atomic magnetic response. The influence of the magnetic nature of the capping layer (Al, Au, and Pt) is also analyzed. Polarized capping layers, such as Pt, magnetically couple the nanostructures and not only increase the effective anisotropy of the system but also enhance the atomic magnetic moment of Co and the global magneto-optical activity.