Preparation and Magneto-Optical Effects of Co-Ag Granular Films

A series of Co-Ag granular films were deposited onto a glass substrate with a thickness on the order of 400nm using the ion-beam cosputtering technique. Granular films ranging in composition from about 0-100% fraction by volume of cobalt have been prepared. Polar Kerr rotation spectra of the films were measured at room temperature in the wavelength region between 400 and 850nm. A maximum Kerr rotation angle (θ_k) of 0.28º was obtained when a magnetic field of 10kOe was applied perpendicular to the film plane. Our results indicate that the Co particle density and the microstructure between the Co particles and Ag matrix may play an important role in the Kerr rotation.