The existence and nature of spin-polarized surface-localized electronic states is expected to have profound consequences for structural, electronic, and spintronic properties of half-metallic materials. It is therefore essential that calculations of such properties take fully into account the possibility of surface reconstruction and segregation. In this work, various {111} surfaces of the ternary half-metallic alloy NiMnSb are investigated via first-principles density functional theory, and their properties are illuminated by comparison with three related binary systems MnSb{0001}, NiSb{0001}, and NiMn{001}. Trends in surface composition are identified, and the close correlation between atomic and electronic structures is discussed.

• Received 23 April 2004

DOI:https://doi.org/10.1103/PhysRevB.70.245401