Phase-dependent electronic and magnetic properties of Ti2C monolayers

Abstract

Achieving tunable magnetism in low-dimensions is an essential step to realize novel spintronic applications. In this manner, two-dimensional transition metal carbides/nitrides (MXenes) with intrinsic magnetism have attracted significant interest. In this study, we extensively examine the structural and magnetic properties of 1T- and 2H-Ti 2C monolayers by using first-principles techniques. We reveal the dynamical stability of both phases by using phonon spectra analysis and a b i n i t i o molecular dynamics simulations. The magnetic ground state is determined by considering all possible spin configurations and taking into account spin-orbit coupling effects, strong onsite Coulomb interaction, and corrected self-interaction terms. Our results indicate that while 1T-Ti 2C is anti-ferromagnetic, 2H-Ti 2C exhibits ferromagnetism, which is stable at/above room temperature. The electronic structure analysis demonstrates that 1T-Ti 2C is an indirect bandgap semiconductor and 2H-Ti 2C is a half-metal with 100% spin-polarization. Additionally, it is shown that the magnetic state is robust against low mechanical deformations and fundamental bandgap (also half-metallic bandgap) can be tuned by compressive/tensile strain. Phase-dependent and tunable electronic and magnetic properties of Ti 2C monolayers offer new opportunities in the field of low-dimensional magnetism.