Layered TiCl2 Monolayer as an Antiferromagnetic Semiconductor

We report layered TiCl2 monolayer to be a robust antiferromagnetic (AFM) semiconductor by investigating its geometry, stability, electronic and magnetic properties using first-principles calculation and Monte Carlo (MC) simulation. The TiCl2 monolayer exfoliated from layered TiCl2 bulk is verified to be an AFM semiconductor with a relatively wide band gap by spinpolarized density of states and energy band structure calculations. Phonon dispersion and elastic modulus calculations show that the TiCl2 monolayer is dynamically and mechanically stable, respectively. The Neel temperature is evaluated to be 368 K by MC simulation based on Ising model. Additionally, the band gap, the magnetic moment of a single Ti atom and the Neel temperature can be significantly tuned by applied biaxial strain, but the AFM semiconducting behavior is robust against the applied strains, indicating that the TiCl2 monolayer is a potential candidate for high-speed AFM spintronic applications.