Platinum overlayer-induced changes of magnetic and magneto-optical properties of ultrathin Co layer

Abstract

Magneto-optical and magnetic properties of Au/Co-wedge/Pt-wedge/Au were investigated as functions of component layer thicknesses. The remanence, coercivity field and saturation of both rotation and ellipticity were deduced from the shape analysis of the magnetic hysteresis loops measured at different positions of the sample by means of the magneto-optical polar Kerr effect magnetometer. For low thickness of platinum overlayer Co-thickness range with perpendicular anisotropy increases, and very high peak of coercivity field was observed. These phenomena are explained in terms of the ternary Co–Pt–Au alloy occurrence with large anisotropy at interface.