Magneto-optic properties of electron cyclotron resonance ion beam sputtered and magnetron sputtered Co/Pt multilayers

An investigation of the magneto-optic properties of single Co films sandwiched by Pt films is presented. The films are grown via electron cyclotron resonance ion beam sputtering and magnetron sputtering. Kerr rotation and ellipticity are measured for the multilayers, varying Pt cap, Co, as well as Pt buffer layer thickness. The set of data allows the separation of optic and magneto-optic contributions to the Kerr signals. The magneto-optic constants (Voigt constants) are determined and compared with literature values. The striking result is the strong difference of the magneto-optic constants for ultrathin and thick Co films. The analysis of the data reveals that for ultrathin films, the Kerr signals have contributions that come presumably from the interfaces, indicative of polarized Pt