Large magnetoresistance in planar Fe/MoS2/Fe tunnel junction

Abstract

We report a large magnetoresistance observed in a Fe/MoS2/Fe tunnel junction, where iron electrodes are attached to the edges of MoS2 nanoribbon (i.e. the current is flowing in the plane of the MoS2 2D monolayer). Using non-equilibrium Green's functions in the framework of density functional approach, our calculations show a large magnetoresistance in Fe/MoS2/Fe junction, with the values up to 150%. The strong coupling between states of Mo atoms at the edge of the MoS2 monolayer and those at the Fe surface have a dramatic effect on the conductance property of the material as well as the MR of the Fe/MoS2/Fe tunnel junction. We conclude that the Fe electrodes polarize the spin states of MoS2 near the interface and efficiently inject carriers into MoS2. We find that the atomically-thin spacers are metallic due to a strong hybridization between the Fe and Mo states at the interface. MoS2 spacers of a larger width remain insulating. We also find that the magnetoresistance of thin MoS2 ribbons (three atomic layers wide) is negative and has a small value. Notably however, as the width of the MoS2 spacer increases, this value turns positive and increases in magnitude.

Electron Spin Dynamics of Two‐Dimensional Layered Materials

“…This comparatively low value compared to the theoretically predicted 9% maximal attainable magnetoresistance indicated that there was room for device optimisation due to the nominally insulating MoS 2 layer showing metallic behavior (perhaps due to strong hybridisation with the Ni and Fe atoms at the MoS 2 ‐Permalloy interface) . To increase magnetoresistance Tarawneha et al proposed the use of lateral heterojunction geometry (i.e., the current flowing in the plane of the MoS 2 monolayer). In this case, the authors used non‐equilibrium Green's functions in the framework of a density functional approach, to calculate that a large 150% magnetoresistance in Fe/MoS 2 /Fe hetero‐junctions could be possible …”

“…To increase magnetoresistance Tarawneha et al proposed the use of lateral heterojunction geometry (i.e., the current flowing in the plane of the MoS 2 monolayer). In this case, the authors used non‐equilibrium Green's functions in the framework of a density functional approach, to calculate that a large 150% magnetoresistance in Fe/MoS 2 /Fe hetero‐junctions could be possible …”

“…[201] This comparatively low value compared to the theoretically predicted 9 % maximal attainable magnetoresistance indicated that there was room for device optimisation due to the nominally insulating MoS 2 layer showing metallic behaviour (perhaps due to strong hybridisation with the Ni and Fe atoms at the MoS 2 -Permalloy interface). [201] To increase magnetoresistance Tarawneha et al [202] proposed the use of lateral heterojunction geometry (i.e. the current flowing in the plane of the MoS 2 monolayer).…”

“…In this case, the authors used noncalculate that a large 150% magnetoresistance in Fe/MoS 2 /Fe hetero-junctions could be possible. [202] Figure 13. A schematic diagram of the four-terminal spin-valve device based on a MoS 2 monolayer.…”

High TMR in MXene-Based Mn2CF2/Ti2CO2/Mn2CF2 Magnetic Tunneling Junction

“…Magnetic tunneling junctions (MTJs), which are one of the most important spintronic devices, are currently utilized in major technological applications, such as magnetic random access memory (MRAM), magnetic sensors, and hard disks. MTJs are formed by placing an insulating separator material between two ferromagnetic electrodes. − The nonmagnetic separator may be an organic material , as well as a traditional inorganic system. Tunnel magnetoresistance (TMR) is the main parameter to assess the quality of MTJ structures.…”