A first-principle study on the two dimensional Janus MXene TaFeC with spin gapless behaviour

Abstract

Based on density functional theory calculations, we have investigated the two-dimensional Janus MXene TaFeC, focusing particularly on the magnetic and electronic properties. It is found TaFeC is dynamically, mechanically, and thermodynamically stable. With both sizable Curie temperature and enhanced out-off plane magneto-crystalline anisotropy energy, the Janus MXene TaFeC has the potential to be applied at finite temperature. The mechanism behind the magneto-crystalline anisotropy energy and magnetism are explained based on perturbation theory and crystal field splitting, respectively. Under biaxial strain, the ferromagnetic order is robust stable. With a various of effective potential on Fe, the electronic structure evolution is studied, where the effective potential of 1.3 eV is a special case. In such case, the Janus MXene TaFeC can be classified as a new type of spin-gapless semiconductor beyond the previous classifications, behaving topological nontrivial edge states.