Room temperature spin valve effect in the NiFe/Gr–hBN/Co magnetic tunnel junction

Abstract

The heterostructures of two-dimensional (2D) atomically thin films have been explored as a model system owing to the unique properties they demonstrate. Graphene and hexagonal boron nitride (hBN) have shown fascinating features in spintronics due to their metallic and tunneling behaviors, respectively. In this work, we report for the first time the room temperature spin valve effect in the NiFe/Gr–hBN/Co configuration. Raman spectroscopy is performed on the graphene–hBN (GBN) heterostructure, which shows the existence of the GBN heterostructure with the corresponding peaks of graphene and hBN layers. The current–voltage characteristic curve of the GBN hybrid structure reveals tunneling features of the device. We demonstrate the tunneling magnetoresistance (TMR) ratio of the GBN spin valve from room temperature to 4.2 K. The magnitude of the TMR ratio is found to increase from −0.85% at 300 K to −1.88% at 4.2 K. Our results could be useful by exploiting GBN heterostructures in magnetic tunnel junctions for future spintronic applications.