Room temperature spin valve effect in NiFe/WS2/Co junctions

Abstract

The two-dimensional (2D) layered electronic materials of transition metal dichalcogenides (TMDCs) have been recently proposed as an emerging canddiate for spintronic applications. Here, we report the exfoliated single layer WS2-intelayer based spin valve effect in NiFe/WS2/Co junction from room temperature to 4.2 K. The ratio of relative magnetoresistance in spin valve effect increases from 0.18% at room temperature to 0.47% at 4.2 K. We observed that the junction resistance decreases monotonically as temperature is lowered. These results revealed that semiconducting WS2 thin film works as a metallic conducting interlayer between NiFe and Co electrodes.

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

“…Note that the resistance decreases with reducing temperature, indicating that the BP behaves as a metal in the spin valve structure as shown in inset of Figure 2(a). The results suggest that the thin BP flake behaves as a conducting thin film rather than a tunnel barrier between the two FM electrodes, which is consistent with the previous works in MoS 2 and WS 2 based spin valve [10,11].…”

“…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.…”

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

“…While this study underlined the problem of MoS 2 integration, the Au layer still led to the limitation of the spin properties of the device. The same year Wu et al [34] attempt was made to demonstrate an MTJ with micron-sized exfoliated WS 2 flakes [38] (see figure 14). The authors exfoliated WS 2 in air on patterned NiFe electrodes and contacted them on the top with Co.…”

Interlayer quality dependent graphene spin valve

“…Now, the interest has turned towards vertical spin valve structures wherein current flows perpendicular to the plane of interlayer. Some research work has also been done on vertical transport in graphene using vertical spin valves, but the quality of the signal and the value of magnetoresistance is always predicted lower than theoretical values [20][21][22][23][24][25].…”