Static and dynamic magnetic properties of CoPt/NiFe bilayers: experiment and modelling

Static and dynamic magnetization behaviours in CoPt(10 nm)/NiFe(t _NiFe) bilayers with variable NiFe thicknesses t _NiFe  =  0.5, 2.5, 4, 5.5 and 8.5 nm, were investigated. Hysteresis cycles were obtained from vibrating sample magnetometry measurements, while Brillouin light scattering technique was used to study the spin waves behaviour in these systems. The experimental results are analysed by means of a simple model taking into account the magnetic inhomogeneity of the CoPt layer composed of magnetic hard and soft zones distinguished by their anisotropy values. This model allows interpreting both the static and the dynamic magnetization measurements. (paper)