Giant magnetoresistance switching in multilayer graphene grown on cobalt.

Magnetic multilayer devices, showing large magnetoresistance (MR) effects, have revolutionized magnetic sensing and data storage sectors over the last few decades. Two-dimensional van der Waals layered materials are relatively new entrants in this area, and these materials can give rise to large MR effects with diverse physical origins. Here we report observation of giant MR switching (∼10 orders of magnitude) in multilayered graphene grown on cobalt (Co) substrates, which persists even at room temperature. The origin of this effect is linked with weak interlayer coupling of the graphene stacks, which gives rise to an 'interlayer MR' effect. This effect is found to be robust against some degree of inhomogeneity in the graphene stack, making it an attractive platform for the emerging area of flexible magnetic sensorics.