The composition in the surface region of the Heusler alloy NiMnSb has been studied using angle-resolved X-ray photoemission spectroscopy, low-energy electron diffraction and spin-polarized inverse photoemission. The results are consistent with a generally Mn-Sb terminal layer, though the surface composition is very sensitive to preparation. The surface composition has a critical influence on the polarization near the Fermi level in spin-polarized inverse photoemission. Under some conditions, the polarization at the Fermi level for normal incidence inverse photoemission can reach values very close to 100% above background.

Ristoiu, Delia; Hordequin, Ch.; Nozie`res, J. P.; Pierre, J.; Stadler, Shane; and Idzerda, Y. U., "Evidence for temperature dependent moments ordering in ferromagnetic NiMnSb(100)" (2001). Peter Dowben Publications. 23.

A quantitative analysis of the surface composition of the Heusler alloy NiMnSb has been undertaken using angle-resolved x-ray photoemission spectroscopy and the surface composition characterized. With sufficient annealing cycles, the stoichiometric surface evolves to a surface that is manganese rich. This indicates that the surface enthalpy is different from the bulk for the Heusler alloy NiMnSb.