Modulating electronic and magnetic properties of ferromagnetic Hf2MnC2O2 MXenes

In this work, density functional theory calculations were carried out to evaluate the electronic and magnetic properties of the uniaxial and biaxial strains applied, and surface defects introduced Hf2MnC2O2 ferromagnetic MXene. The bare Hf2MnC2O2 monolayer is an indirect bandgap semiconductor with a 0.282 eV bandgap. Our calculations show that the semiconductor-to-half-metal phase transition occurs at 7%, and 9% under uniaxial tensile strain in zig-zag and armchair directions, respectively. The same phase transition can be seen at 8% biaxial tensile strain. This ferromagnetic semiconductor can become a metal under small uniaxial and biaxial compressive strains. We are also able to show that the bare Hf2MnC2O2 monolayer contains an easy-plane anisotropy. The anisotropy of the monolayer transforms into an enhanced, easy-axis anisotropy when the O vacancies and the H adatoms are introduced.