Enhanced magnetic response and metallicity in AB stacked bilayer graphene via Cr-doping

First-principles study for the electronic and magnetic properties of Cr atom doping in lower layer of AB bernal stacked bilayer graphene (BLG) is presented. This doping is analysed in three different configurations; (i) Hollow type (above the centre of C hexagon), (ii) Top-type (directly on the top of any C atom) and (iii) Bridge type (mid point of any C–C bond). It has been observed that the doping of Cr atom enlarges the interlayer spacing in BLG as compared to pure one. The Top-type (T-type) doping is found to be most stable energetically. The doping of Cr atom in all configurations generates the large spin polarization and induces the appreciable magnetic moment. Half metallicity has been obtained in Hollow type (H-type) doping with a suitable band gap of 0.28 eV in minority spin channel. The origin of magnetism has been identified via interactions of 3d-states of doped Cr atom with p-states of inequivalent C atoms present in the vicinity of doping site. The electron densities plots also confirm the metallic nature of Cr-doped BLG. Our results reveal that the resultant BLG has potential for futuristic applications such as high frequency transistors, spintronics, photodetectors and energy resources. - Highlights: • Cr-doping in bilayer graphene induces magnetic channel. • Half metallicity is observed only in H-type Cr-doping in graphene. • T-type doping is most energetically stable among all types (H-type, B-type and T-type). • The strong hybridization of Cr-3d states with C-p states governs the magnetism in BLG