1Department of Electronics and Tianjin Key Laboratory of Photo-Electronic Thin Film Device and Technology, Nankai University, Tianjin 300071 2Department of Material Science and Engineering, the University of Texas at Dallas, Richardson 75080, USA
Abstract：We study the electronic and magnetic properties of an oxygen-deficient perovskite Ca$_{2}$Mn$_{2}$O$_{5}$ based on the first principle calculations. The calculations show that the ground state of Ca$_{2}$Mn$_{2}$O$_{5}$ is a D-type anti-ferromagnetic structure with the anti-ferromagnetic spin coupling along the $c$-direction. The corresponding electronic structure of the D-type state is investigated, and the results display that Ca$_{2}$Mn$_{2}$O$_{5}$ is an insulator with an indirect energy gap of $\sim$2.08 eV. By the partial density-of-state analysis, the valence band maximum is mainly contributed to by the O-2$p$ orbitals and the conduction band minimum is contributed to by the O-2$p$ and Mn-3$d$ orbitals. Due to the Coulomb repulsion interaction between electrons, the density of state of Mn-3$d$ is pulled to $-$6–$-$4.5 eV.
2017, Vol. 34 
