Spin-Valve Effect in NiFe/MoS₂/NiFe Junctions

TLDR

Two‑dimensional transition‑metal dichalcogenides have emerged as promising spintronic materials because of their unique crystal structure and anisotropic electronic properties. The study introduces the first MoS₂‑based spin‑valves that employ a monolayer MoS₂ spacer between Permalloy electrodes. The devices rely on strong hybridization at the MoS₂/Permalloy interfaces and are characterized by first‑principles electron‑transport calculations. The MoS₂ layers behave metallically and generate a spin‑valve effect up to 240 K, with experimental magnetoresistance up to 0.73 % and theoretical MR of ~9 %, confirming TMDs as promising spacers for magnetic tunnel junctions.

Abstract

Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) have been recently proposed as appealing candidate materials for spintronic applications owing to their distinctive atomic crystal structure and exotic physical properties arising from the large bonding anisotropy. Here we introduce the first MoS2-based spin-valves that employ monolayer MoS2 as the nonmagnetic spacer. In contrast with what is expected from the semiconducting band-structure of MoS2, the vertically sandwiched-MoS2 layers exhibit metallic behavior. This originates from their strong hybridization with the Ni and Fe atoms of the Permalloy (Py) electrode. The spin-valve effect is observed up to 240 K, with the highest magnetoresistance (MR) up to 0.73% at low temperatures. The experimental work is accompanied by the first principle electron transport calculations, which reveal an MR of ∼9% for an ideal Py/MoS2/Py junction. Our results clearly identify TMDs as a promising spacer compound in magnetic tunnel junctions and may open a new avenue for the TMDs-based spintronic applications.