Synthesis, magnetic ordering, transport studies on spintronic device heterostructures of 2D magnetic materials: A review

Abstract

2D magnetic materials are either monolayer or few layers of 3D van der Waals materials (graphite, MoS2, MoSe2, WSe2, CrI3 etc.) which can be easily cleaved in perpendicular direction by simple and cost-effective exfoliation techniques. This review summarizes the synthesis methods, magnetic properties and transport measurements done on magnetic tunnel junctions, spin valves, multilayer heterostructures made up of 2D magnetic materials. This research area was started in 2017 when intrinsic 2D ferromagnetic ordering was observed in two systems, Cr2Ge2Te3 and CrI3 which was otherwise not possible theoretically as the Mermin–Wagner theorem. As per this theorem, thermal fluctuation will abolish long-range magnetic order in 2D system at finite temperature although 2D Ising type ferromagnetism is possible. Post 2017, there has been extensive research efforts done to explore promising 2D magnetic materials theoretically as well as experimentally as these magnetic 2D layers in vDW heterostructures will open up new possibilities for designing efficient low power- high speed spintronic devices such as magnetic tunnel junctions (MTJs), spin valves, spin filters, spin-FETs, magnetic memory devices and spin torque nano-oscillators.