Temperature-dependent spin dynamics in WSe2/Pt/CoFe trilayers

In this work, magnetic anisotropy and magnetic damping factor (α
s
) were studied at different temperatures (T) for the tungsten diselenide (WSe
2
)/Pt/CoFe heterostructure samples with various WSe
2
monolayer numbers (n
ML
). We observed that the WSe
2
underlayer could weaken the perpendicular magnetic anisotropy due to the increased interfacial roughness and decreased orbital hybridization effect. In particular, the insertion of WSe
2
leads to a rather high α
s
, which mainly arises from the contributions of interfacial two-magnon scattering (TMS) and spin pumping by the WSe
2
layer. When T is gradually reduced below 200 K, the magnetic damping factor of WSe
2
/Pt/CoFe exhibits a much strong temperature dependence, as compared with the single CoFe films or Pt/CoFe bilayer. We consider the significant drop in damping at T<200 K is due to the decreased TMS scattering since the interfacial random spins become ordered. Our work elucidates the significant implications of two-dimensional materials on the magnetic properties, which will be valuable for the development of transition-metal dichalcogenides based spintronics devices.