Study of Electronic Structure and Topological Phenomena in Ti₂N MXene

The evolution of structural and electronic properties of graphene-like titanium nitride based MXenes have been studied with different functional groups (F, O, H, and OH) employ-ing first principles electronic structure calculations. The calculated formation and cohesive energies reveal the chemical stability of all MXenes and MAX phase. The MAX phase and all the studied defect free functionalized MXenes are metallic in nature except for oxygen termination, which expected to be semi-metallic . The bare MXene is nearly half metallic ferromagnet but after surface termination, it’s ferromagnetism gets destroyed. The strain effect significantly influences the Fermi level with the formation of Dirac topology. The variable topological phenomena have been studied in pristine and defected MXenes. Interestingly, the defect on MXene sheet Ti₂NO₂ significantly changed the electronic properties. Further, the Cr and Co substitutions in Ti₂NO₂ allow to convert the system to be ferromagnetic and para-magnetic with half metallicity respectively. However, Mn substitution preserves metalicity with ferromagnetic properties.