Ultrafast laser-induced precession dynamics in perpendicular artificial ferrimagnetic [D0₂₂-Mn₃Ga/Co₂MnSi]₅ superlattices

Artificial ferrimagnetic [D0(22)-Mn3Ga/Co2MnSi](N) superlattices ([Mn3Ga/CMS](N )SLs) combining perpendicular magnetic anisotropy as well as exceptional thermal and magnetic stability hold promises in functional spintronic devices. However, the relevant precession dynamics are still lacking. Here, we report on the magnetic dynamic properties in [Mn3Ga/CMS](5) SLs investigated by the time-resolved magneto-optical Kerr effect (TRMOKE) measurements. The magnetization precession process and magnetic damping constant (alpha(0)) of [Mn3Ga/CMS](5) SLs rely heavily on the thickness of Mn3Ga layer (t(Mn3Ga)). In addition, alpha(0) is found to be higher with increasing t(Mn3Ga), but is not simply scaled by the uniaxial magnetic anisotropy (K-u), which can be ascribed to the contribution of spin-orbit interaction combined with the additional contributions, like spin-pumping. Furthermore, a large K-u value of 1.33 Merg/cm(3) and a low alpha(0) of 0.022 have been simultaneously obtained in [Mn3Ga/CMS](5) SL with t(Mn3Ga )= 1.5 nm. This study contributes to the design of high-performance spintronic devices based on [Mn3Ga/CMS](N) SLs.