Room-temperature spin-valve devices based on Fe₃GaTe₂/MoS₂/Fe₃GaTe₂ 2D van der Waals heterojunctions

The spin-valve effect has been the focus of spintronics over the last decades due to its potential for application in many spintronic devices. Two-dimensional (2D) van der Waals (vdW) materials are highly efficient to build spin-valve heterojunctions. However, the Curie temperatures (T_C) of the vdW ferromagnetic (FM) 2D crystals are mostly below room temperature (∼30-220 K). It is very challenging to develop room-temperature, FM 2D crystal-based spin-valve devices. Here, we report room-temperature, FM 2D-crystal-based all-2D vdW Fe₃GaTe₂/MoS₂/Fe₃GaTe₂ spin-valve devices. The magnetoresistance (MR) of the device was up to 15.89% at 2.3 K and 11.97% at 10 K, which are 4-30 times the MR of the spin valves of Fe₃GeTe₂/MoS₂/Fe₃GeTe₂ and conventional NiFe/MoS₂/NiFe. The typical spin valve effect showed strong dependence on the MoS₂ spacer thickness in the vdW heterojunction. Importantly, the spin valve effect (0.31%) robustly existed even at 300 K with low working currents down to 10 nA (0.13 A cm^-2). This work provides a general vdW platform to develop room-temperature, 2D FM-crystal-based 2D spin-valve devices.