Magnetization curves of palladium/cobalt multilayers with perpendicular anisotropy

In a ferromagnetic thin film with strong perpendicular anisotropy, saturation may be reached at fields lower than the magnetization. This field is calculated for a multilayer with alternating ferromagnetic and nonmagnetic layers assuming that the stripe domains are oriented only up or down along the anisotropy axis. The results are compared with experimental data on Pd/Co multilayers with ultrathin Co layers. The agreement is very good if we take sw=1×10-3 J/m2 as the energy of walls between the domains. It is argued also that with other materials, high perpendicular relative remanence may be achieved when multilayers with suitable parameters are used.