Variable angle magnetometry for exchange-coupled multilayers with in-plane and perpendicular anisotropy

Co/Pd multilayers, including exchange coupled structures with thin layers of Co with different exchange coupling strengths, were investigated using variable angle magnetometry. Hysteresis loops of perpendicular and in-plane components of magnetization were measured using two-axis vibrating sample magnetometer and variable angle magneto-optical Kerr effect system. Co/Pd multilayer structures have high perpendicular remanence and the magnetization reversal mechanism is mainly domain wall motion. For the systems with Co and Co/Pd multilayers, the magnetization reversals of high coercivity (Co/Pd) multilayer and low coercivity Co single layer were found to be independent, if the soft layer (Co) is thicker than 2 nm. In the samples with a high degree of exchange coupling, the magnetization of the multilayer has two components, normal and in-plane. The proportion between them varies with field strength and orientation of the sample. Taking this into account, it was possible to determine the anisotropy energy of the (Co/Pd) multilayer, which is in the range of 400-420 kJ/m ³.