Abstract
Magnetization reversal time in ferrimagnetic material is compared with that in ferromagnetic material. Since ferromagnetic material is in a state of underdamping, the reversal time is relatively long. A formula for reversal time in ferrimagnetic material is deduced under the assumption that the effective Gilbert damping parameter αeff is inversely proportional to the net angular momentum. In the case of g1=g2, where g1 and g2 are the g-factors of the first and second sublattices, respectively, the reversal time in ferrimagnetic material is much shorter than that in ferromagnetic material because αeff in ferrimagnetic material can be adjusted so that αeff=1. Furthermore, in the case of g1≠g2, the reversal time becomes much shorter than that when g1=g2 because a large net magnetization and small net angular momentum can be realized.
