Study of Magnetic Heterostructure MgO/CoFeB/Ta Using the Harmonic Method

Structures of the heavy metal/ferromagnetic type are of great interest since magnetization can be switched in them due to the transfer of the spin torque by the spin-orbit interaction mechanism. This type of switching has advantages for the applications in magnetoresistive memory cells. Employing this mechanism, the memory cells can have a simple structure, and the magnetization switching requires less energy than in the case of direct spin torque transfer. We have studied a sample of MgO/CoFeB/Ta with in-plane magnetization and high spin polarization. In this work, the Hall adiabatic harmonic voltage method is used to study the effective damping coefficient, as well as to estimate the values of the effective fields that arise in such structures due to the spin-polarized current.