Oxygen-induced enhancement of the spin-dependent effects in electron spectroscopies of Fe(001)

Oxygen adsorption in an ordered p(1 X 1) fashion on the Fe(001) surface has been studied by empty states spectroscopies using a spin-polarized electron beam. The low-energy electron absorption and reflection display a much larger spin dependence in Fe(001)-p(1 X 1)O than in Fe(001). Peak values of the spin asymmetries of the absorbed (reflected) current larger than 13% (45%) at around 9-11 eV above the Fermi level are found. Spin-resolved inverse photoemission reveals that in the same energy range the exchange splitting between majority- and minority-spin states in Fe(001)-p(1 X 1)O is similar to 50% larger than in the clean surface. [S0163-1829(99)09905-1].