Spin-dependent electronic transport in NiMnSb/MoS2(001)/NiMnSb magnetic tunnel junction

Abstract

Half-metallic Heusler alloy compounds with Curie temperatures above room temperature are suitable candidate electrode materials for injecting large spin-polarised charge carriers into the semiconducting barriers at the ferromagnet semiconductor junction to obtain highly spin-polarised current. Combining the density functional theory and non-equilibrium Green's function method, the electronic structure, spin dependent electron transport in NiMnSb/MoS2(001)/NiMnSb is studied. The possibilities of injecting 100% spin-polarised electron into MoS2 using half metallic NiMnSb as an electrode, the layer dependent, and the effect of the type of interface on electronic structure and spin-transport properties in magnetic tunnel junction devices are studied. We show that the half-metallicity of NiMnSb(111) is preserved at the interface between the half-Heusler alloy NiMnSb and MoS2. NiMnSb keeps a fully spin-polarised state in the majority spin channel at the interface between NiMnSb and MoS2, injecting fully spin-polarised electrons into the semiconductor. The device based on NiMnSb/MoS2(single layer)/NiMnSb has a metallic interface. Metal-induced states in the spin-majority channel of MoS2 are seen after making an interface with half metallic NiMnSb. In contrast, the NiMnSb/MoS2(three layers)/NiMnSb interface with a multilayer of MoS2 has a band gap region, and electrons can tunnel through the junction. The Mn-S interface is more conducting than the Sb-S interface due to the strong bonding of Mn and S atoms at the Mn-S interface.