Resistivity dependence of the spin mixing conductance and the anisotropic magnetoresistance in permalloy

Microwave spin pumping at ferromagnetic resonance from ferromagnetic films into nonmagnetic films is an efficient method to realize spin injection. The spin injection efficiency is proportional to the spin mixing conductance and can be detected by measuring voltages converted from spin current via the inverse spin Hall effect. In this work, we modified the properties of the ferromagnetic layer by thermal annealing. The results show that the crystal quality of the ferromagnetic films, as well as the magnetic properties has been greatly modified while the spin mixing conductance is insensitive to it. The work represent an incentive to work on engineering the spin Hall angle of the nonmagnetic layer to improve the spin Hall effect or the inverse spin Hall effect.