Room-temperature spin-valve devices without spacer layers based on Fe₃GaTe₂ van der Waals homojunctions

In the advancement of spintronic devices, spin valves play a critical role, especially in the sensor and information industries. The emergence of two-dimensional (2D) van der Waals (vdW) magnetic materials has opened up new possibilities for the development of high-performance spin-valve devices. However, the Curie temperature (T_C) of most 2D vdW ferromagnets falls below room temperature, resulting in a scarcity of room-temperature spin-valve devices. In this study, we have prepared spin-valve devices without spacer layers based on Fe₃GaTe₂ vdW homojunctions and observed notable two-state magnetoresistance (MR) from 2 K to room temperature. A maximum MR of 50% surpasses some heterojunctions with spacer-layer structures and it remains 0.6% at room temperature. Furthermore, spin-valve devices exhibit favorable ohmic contact and low operating current as low as 10 nA. These findings demonstrate the enormous potential of Fe₃GaTe₂-based room-temperature devices and the simplified two-layer structure shows significant prospect in the context of the ongoing trend towards miniaturization of contemporary devices.