The surface composition and spin polarization of NiMnSb epitaxial thin films

The composition in the surface region of the Heusler alloy NiMnSb has been studied using angle-resolved X-ray photoemission spectroscopy low-energy el ectron diffraction and spin-polarized inverse photoemission. The results ar e? consistent with a generally Mu-Sb terminal layer, though the surface com position is very sensitive to preparation. The surface composition has a cr itical influence on the polarization near the Fermi level in spin-polarized inverse photoemission. Under some conditions, the polarization at; the Fer mi level far normal incidence inverse photoemission can reach values very c lose to 100% above background.