2D-Double transition metal MXenes for spintronics applications: surface functionalization induced ferromagnetic half-metallic complexes

MXenes are rapidly emerging two-dimensional (2D) materials with thickness, composition, and functionalization-dependent outstanding properties having applications in diverse fields. To disclose the nano-spintronic applications of 2D-double transition metal (DTM) carbide and nitride-based pristine and surface-functionalized MXenes (M-2'M '' X2Tx, M' and M '' = Cr, Mo, W; X = C/N; T = -F/-OH/=O), a systematic investigation has been performed on their structural stability, magnetic properties and electronic structure using spin-polarized first-principles calculations. 36 stable functionalized MXenes were screened from 144 explored DTM based MXenes. The explored materials exhibit striking properties, having a wide range of magnetic ground states, from non-magnetic to ferromagnetic, and then to antiferromagnetic, accompanied by metallic to half-metallic or gapless half-metallic properties, depending on the transition metal(s) and terminating group. Mo and W-based MXenes are found to be nonmagnetic and metallic, whereas Cr-Mo and Cr-W-based MXenes are magnetic with varying metallic behavior. W2CrN2O2 and Mo2CrN2O2 systems are found to be ferromagnetic half-metallic 2D materials with a direct band gap of 1.35 eV and 0.77 eV respectively, in the minority spin channel. A comprehensive study on DTM MXenes, which show intrinsic half-metallic properties along with robust ferromagnetism, opens up a class of promising new 2D materials with tunable magnetic and electronic properties for potential device applications in nano-spintronics and electronics.

Automated summary

MXenes are a rapidly emerging class of two-dimensional materials with outstanding properties that can be tuned by their thickness, composition, and functionalization. This study systematically investigated the structural stability, magnetic properties, and electronic structure of various functionalized MXenes based on double transition metals (DTM). The results revealed a wide range of magnetic ground states and electronic properties, making these materials promising for potential applications in nano-spintronics and electronics.