POLARIZED UNOCCUPIED STATES OF OXYGEN ON FE(100)

We present spin-polarized inverse photoemission results from oxygen ad sorbed on the Fe(100) surface. Results for the clean surface indicate that the crystalline quality influences the spectra, while no surface state contribution is detected. When Fe(100)1 X 1-0 formation occurs a completely polarized adsorbate-derived feature is observed. This stat e displays a minority spin character at 1.8 eV above the Fermi level w hile no majority spin counterpart structure is present in the spectra. The present results are in contrast with previous expectations based on theoretical calculations.