First-principles study of the (001) surface of half-metallic cubic BaCrO3

First-principles calculations have been performed to study the (001) surfaces of half-metallic cubic BaCrO3 with BaO and CrO2 terminations by employing density function theory under the generalized gradient approximation (GGA)+U (Hubbard parameter). Surface relaxations reveal that the CrO2-terminated surface could be rougher than the BaO-terminated surface and an oscillatory (−+−) damping (|Δd12|>|Δd23|>|Δd34|) relaxation phenomenon appears for both the BaO-termination and the CrO2-termination. Meanwhile, the grand thermodynamic potential F indicates that only the BaO-terminated surface can exist steadily in the range of the accessible values of the CrO2 chemical potential. The electronic structure calculations predict that BaO-terminated surface preserves the bulk's half-metallic property. For the CrO2-terminated surface, surface states can be identified which result in the deterioration of its half-metallicity.