The new antiferromagnetic semiconductor NaMn2O4: Predicting from first-principle theory

The electronic and magnetic properties of the calcium ferrite-type NaMn2O4 were studied using the full-potential linearized augmented plane wave method. The results indicate that an antiferromagnetic ground state is energetically favored over ferromagnetic and ferrimagnetic state. NaMn2O4 in the antiferromagnetic configuration is semiconductor both from the GGA and GGA+U   calculations. The spin magnetic moments and density of states of Mn atoms show that Mn3+/Mn4+ charge ordering presents, in agreement with the experimental observation. Accompanying the charge and antiferromagnetic spin orderings, an orbital ordering exists in NaMn2O4 due to the Jahn-Teller effect of Mn3+ ions.