Spin-Valve Effect in NiFe/MoS₂/NiFe 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.

2D-MTJs: introducing 2D materials in magnetic tunnel junctions

“…Two studies have managed to derive large MoS 2 layers on ferromagnetic spin sources [33,34]. In 2015, Wang et al [33] described the introduction of MoS 2 layers in MTJs.…”

“…Two studies have managed to derive large MoS 2 layers on ferromagnetic spin sources [33,34]. In 2015, Wang et al [33] described the introduction of MoS 2 layers in MTJs. The authors developed a process for MoS 2 growth which required a wet transfer step for integration with ferromagnets, leading to the same issues already encounter ed with graphene (as shown in section 3).…”

Magnetoresistance Effect in NiFe/BP/NiFe Vertical Spin Valve Devices

“…Recently, the 2D nanomaterials have also been demonstrated to have potential for application in the field of spintronics [4][5][6][7][8][9][10][11]. The 2D materials have been largely researched as nonmagnetic interlayer of spin valve, which is similar to traditional magnetic tunneling junctions consisting of two ferromagnetic (FM) layers separated by a nonmagnetic insulating spacer, usually Al 2 O 3 and MgO, and the resistance depends on the magnetization orientation of two ferromagnetic electrodes [12,13].…”

“…Later on, magnetoresistance (MR) was measured at room temperature in graphene vertical spin valve [7,8]. Subsequent works reported spin-dependent transport in h-BN and transition metal dichalcogenides (TMDs), such as MoS 2 and WS 2 [9][10][11]. These studies suggest that the 2D nanomaterials may be promising for spintronic applications.…”

Current-induced spin polarization and spin-orbit torque in graphene

“…Indeed, such a switching was observed experimentally in a recent paper by Wang et al 54 However, instead of graphene they used MoS 2 -another two-dimensional honeycomb crystal.…”