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 (WSe₂)/Pt/CoFe heterostructure samples with various WSe₂ monolayer numbers (n_ML). We observed that the WSe₂ underlayer could weaken the perpendicular magnetic anisotropy due to the increased interfacial roughness and decreased orbital hybridization effect. In particular, the insertion of WSe₂ leads to a rather high α_s, which mainly arises from the contributions of interfacial two-magnon scattering (TMS) and spin pumping by the WSe₂ layer. When T is gradually reduced below 200 K, the magnetic damping factor of WSe₂/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.