Surface properties of the (001) surface of cubic BaMnO3: A density functional theory study

Abstract

We have theoretically investigated surface properties of the (001) surface in cubic barium manganese (BaMnO3) by the full-potential linear augmented plane wave methods within the local spin-density approximation. We present and discuss the electronic properties of the (001) surface of cubic BaMnO3 with BaO- and MnO2-terminations. Surface structure, Mulliken effective atomic charges, surface energies and stability, band structure, and partial density of states have been obtained. For the BaO-terminated surface, we find that all layer atoms relax inward (toward the central layer), while for the MnO2-terminated surface all layer atoms relax outward (toward the vacuum). The largest relaxations emerge on the first-layer atoms on the two terminations. The surface rumpling of the BaO-terminated is much larger than that of the MnO2-terminated surface. Based on the results of the calculated surface energies and stability, we obtain that only the BaO-terminated surface can exist in the (001) surface of cubic BaMnO3. From the analysis of their band structure, we can see that the BaO-terminated surface has obvious half-metallic character, compared with the bulk materials and the MnO2-terminated surface.