Room-Temperature Spin-Valve Effect in Fe₃GaTe₂/MoS₂/Fe₃GaTe₂ 2D van der Waals Heterojunction Devices

Spin-valve effect has been the focus of spintronics over the last decades due to its potential in many spintronic devices. Two-dimensional (2D) van der Waals (vdW) materials are highly expected to build the spin-valve heterojunction. However, the Curie temperatures (TC) of the vdW ferromagnetic 2D crystals are mostly below room temperature ( 30-220 K). It is very challenging to develop room temperature, ferromagnetic (FM) 2D crystals based spin-valve devices which are still not available to date. We report the first room temperature, FM 2D crystal based all-2D vdW Fe3GaTe2/MoS2/Fe3GaTe2 spin valve devices. The Magnetoresistance (MR) of the all- devices is up to 15.89% at 2.3 K and 11.97% at 10 K, 4-30 times of MR from the spin valves of Fe₃GaTe₂/MoS₂/Fe₃GaTe₂ and conventional NiFe/MoS₂/NiFe. Typical spin valve effect shows strong dependence on MoS2 spacer thickness in the vdW heterojunction. Importantly, the spin valve effect (0.31%) still robustly exists at 300 K with low working currents down to 10 nA 0.13 A/cm$²$. The results provide a general vdW platform to room temperature, 2D FM crystals based 2D spin valve devices.