Field angle-independent high magnetoresistance and field angle-dependent coercivity in Fe3GaTe2/Phosphorus all-van der Waals spin valves at room temperature
摘要
Two-dimensional (2D) spin valves are important for energy-efficient memory and computation devices but remain limited in achieving high magnetoresistance (MR) ratios at room temperature due to the lack of suitable ferromagnetic materials, optimal spin transport channel spacers, and great challenges in atom-level interface control in heterostructures. Here we report a record room temperature MR up to 103% for all-van der Waals (vdW) heterostructures by employing vdW ferromagnetic Fe3GaTe2 (FGaT) electrodes with vdW monoelemental black or violet phosphorus spacers. Notably, these devices exhibit magnetic field angle-independent MR while retaining anisotropic coercivity. This behavior originates from domain wall motion-driven magnetization reversal and the strong perpendicular magnetic anisotropy of the FGaT. First‑principles transport calculations reveal an intrinsic zero‑bias MR of up to 330% at the Fermi level for ideal interfaces and a monolayer spacer, supporting the high spin‑polarized transport capability of these heterostructures. The experimental room temperature MR is lower due to finite bias, temperature, spacer thickness, and realistic interface conditions. These results demonstrate the potential of 2D vdW monoelemental phosphorus as a high-efficiency spin-transport channel in room temperature all-vdW spin valves and provide a framework for designing field-orientation-resilient non-volatile spintronic memory devices.