Magnetic and electronic structure calculations of antiferromagnetic Mn2As

Magnetic and electronic structure calculations are performed for Mn₂As with antiferromagnetic (AFM), ferromagnetic (FM), and ferrimagnetic (FIM) spin ordering, using the full-potential linearized augmented plane-wave (FLAPW) method based on the generalized gradient approximation (GGA). It is shown that AFM is the magnetic ground state of Mn₂As, which is in agreement with the experimental observations. At a low temperature (0 K), AFM-FIM transition is also predicted which is consistent with the previous predictions. The ground state stability of the magnetic structure of Mn₂As is attributed to the nearest Mn (I) and Mn (II) antiferromagnetic interaction. The calculated magnetic moment of Mn (II) is found to be in good agreement with the neutron diffraction experiment while there is a disagreement for the magnetic moment of Mn (I). The different magnetic moments are reflected in the electronic structures of Mn₂As and the exchange splitting between Mn atoms is shown to be an intra-atomic effect.