Interface effects of the magnetic properties in Nd/Ni80Fe20 bilayer films

The magnetic properties of Nd/Ni80Fe20 (Py) bilayer films with different layer thicknesses were investigated. Hysteresis loops were measured at different temperatures, an exchange bias effect is found at low temperature due to the Nd/Py interface. By fitting the temperature dependence of the saturation magnetization, the Neel point of Nd layer is obtained. Ferromagnetic resonance (FMR) experiments were carried out at room temperature as a function of Nd layer thickness. The damping parameter obtained by theoretical fitting of the FMR linewidth shows an increasing trend with increasing Nd layer thickness, which is taken as an indication of the spin pumping effect.