Magnetoresistance in Co/2D MoS₂/Co and Ni/2D MoS₂/Ni junctions

Semiconducting single-layer (SL) and few-layer MoS₂ have a flat surface, free of dangling bonds. Using density functional theory coupled with non-equilibrium Green's function method, we investigate the spin-polarized transport properties of Co/2D MoS₂/Co and Ni/2D MoS₂/Ni junctions with MoS₂ layer numbers of N = 1, 3, and 5. Well-defined interfaces are formed between MoS₂ and metal electrodes. The junctions with a SL MoS₂ spacer are almost metallic owing to the strong coupling between MoS₂ and the ferromagnets, while those are tunneling with a few layer MoS₂ spacer. Both large magnetoresistance and tunneling magnetoresistance are found when fcc or hcp Co is used as an electrode. Therefore, flat single- and few-layer MoS₂ can serve as an effective nonmagnetic spacer in a magnetoresistance or tunneling magnetoresistance device with a well-defined interface.