Magneto-Plasmonic Effect in Cobalt Thin Film Incorporating Core–Shell Ag@Au Nanoparticles

We report enhanced magneto-optical Kerr rotation in the magneto-plasmonic structure of a cobalt thin film incorporating silver/gold core–shell nanoparticles. Metallic nanoparticles with core–shell structure of silver/gold were fabricated by laser ablation in liquid method and the magneto-optical medium was prepared by electron beam deposition technique. Excitation of localized surface plasmon resonance was demonstrated for various incidence angles. The experimental results show direct evidence for localized surface plasmon resonance enhancement effect on the polar magneto-optical Kerr effect of the cobalt thin film.