The magneto-optical Kerr properties of Co-Ag annealed granular films

A series of CoxAg100-x granular films was prepared by ion beam sputtering and annealed at 100 degreesC, 250 degreesC, 400 degreesC, 500 degreesC, respectively. The optical constants, the complex dielectric function and magneto-optical Kerr parameters were measured at room temperature. It was found that Ken rotation and ellipticity with increasing of the Co content. For the samples Co17Ag83, the strong Kerr effect enhancement is observed around the Ag plasma edge. With the annealing temperature increasing, the enhancement peak shifted toward the low photon energy region. From the analysis of the numerical calculations, it is concluded that the magneto-optical Kerr effect enhancement (MOKE) is due to the presence of the steep plasma edge.