Micromagnetic study of subnanosecond magnetic switching in perpendicular multilayers

Abstract

Measurements and micromagnetic modeling results are presented of the subnanosecond magnetization reversal process of perpendicularly magnetized (CoCr/Pt) multilayers. The switching time of the magnetization is primarily dependent on the field strength and field bias angle to the perpendicular direction. The intergranular exchange coupling results in a domino-type magnetization reversal, significant delay in the media response far from the gap edge, and an asymmetry between the maximum upper and lower magnetization levels attained in response to a periodically varying head field. The thermal excitations of the magnetization assist the switching of the magnetization, however, their effect is small and can be neglected, to first order, in studies of high-speed switching of the magnetization in response to a change in the head field polarity. The gyromagnetic switching in the multilayered film appears to be heavily damped.