Polar Kerr spectroscopic magneto-optics in Au/Co-Ag/Ag granular thin films on glass: Experiments and simulation

In Au/Co-Ag/Ag granular thin films, linear polar magneto-optical Kerr spectra were measured in the 250-800 nm wavelength range. These experimental spectra were compared to magneto-optical (MO) simulations using an optical multilayer model based on matrix formalism. MO simulations using homogenous layers of uniform thickness led to a great difference of amplitude and shape between the measured and simulated curves. Atomic force microscopy and scanning electron microscopy images were used to estimate the granular structure of the samples and determine the mean diameter and height, respectively of the Ag and Ag-Co islands of each layer. Using this granular structure in our MO simulations, a reasonable agreement between the simulations and MO experiments was obtained for both the Kerr rotation and ellipticity spectra.