Fe3GaTe2/MoSe2 ferromagnet/semiconductor 2D van der Waals heterojunction for room-temperature spin-valve devices

Abstract

A spin-valve heterojunction plays a vital role in many technologies such as non-volatile magnetic random-access memories (MRAMs) and high-density magnetic recording. In particular, a spin-valve device based on two-dimensional van der Waals (vdW) heterostructures offers an excellent route for low power consumption and miniaturization of spintronic devices. However, the Curie temperature (T_C) of 2D vdW ferromagnetic crystals is mostly lower than room temperature, and the spin-valve heterostructures of room-temperature ferromagnetic 2D crystals are rare. It is necessary and very challenging to realize the room-temperature spin-valve heterojunctions of 2D ferromagnetic crystals. We prepare a 2D room-temperature, ferromagnetic crystal based 2D vdW Fe₃GaTe₂/MoSe₂/Fe₃GaTe₂ ferromagnet/semiconductor 2D van der Waals heterojunction. The magnetoresistance (MR) of this heterojunction device reaches 3.7% at room temperature (T = 300 K) and 37.7% at 2 K. Importantly the spin-valve effect can still operate at bias currents as low as 10 nA at room temperature in the ferromagnet/semiconductor 2D van der Waals heterojunction. We open a realistic path to 2D magnetic tunnel junctions for next generation spintronic applications at room temperature.