LONGER LIVING MAJORITY THAN MINORITY IMAGE STATE AT FE(110)

A strongly spin-dependent lifetime is reported for the n = 1 image-pot ential surface state at Fe(110). Spin-resolved inverse photoemission m easurements reveal an intrinsic linewidth of 140 +/- 10 meV for the mi nority image state, about twice as large as the 70 +/- 10 meV observed for the majority state. The spin dependence of the lifetime can be ex plained in terms of the spin-dependent density of bulk electronic stat es in iron, on the assumption that escape into bulk states accompanied by electron-hole-pair production is the main decay channel. The bindi ng energies are magnetically split by 57 +/- 5 meV. This result suppor ts the predicted predominant influence of the spin-polarized substrate potential on the binding energy, modified by a small effect of the sp in-polarized surface barrier.