Ultrafast Magnetization Precession in Perpendicularly Magnetized L10-MnAl Thin Films with Co2MnSi Buffer Layers

Perpendicularly magnetized L10-MnAl thin films with Co2MnSi buffer layers were prepared on GaAs (001) substrates by molecular-beam epitaxy (MBE).The samples with high crystalline quality show a maximum uniaxial perpendicular magnetic anisotropy constant of 1.4 × 107 erg/cm3.Ultrafast spin dynamics with a magnetization precession frequency up to 200 GHz was investigated by using time-resolved magneto-optical Kerr effect (TRMOKE) measurements,from which the Gilbert damping constant α of epitaxial L10-MnAl thin films is evaluated to be less than 0.0175.This work provides an important reference for analyzing the current-induced magnetization switching process in MnAl-based spintronic devices.