Magnetization, spin polarization, and electronic structure of NiMnSb surfaces

NiMnSb, a haff-Heusler alloy, is one of the local-moment ferromagnets with unique properties for future applications. Calculations for the bulk band structure predict exclusively majority bands at the Fermi level, thus indicating 100% spin polarization there. As one thinks about applications and the design of functional materials, the influence of reduced dimensions, e.g., in ultrathin films or at interfaces, must be considered. The magnetization, spin polarization, and electronic structure are expected to be sensitive to stuctural and stoichiometric changes. In this paper, we report on investigations of the spin-dependent unoccupied electronic states at NiMnSb surfaces by appearance potential spectroscopy and inverse photoemission. The data are discussed along with results oil the surface structure and magnetic order.