MAGNETICALLY SPLIT SP-DERIVED STATES IN FCC-LIKE FE CU(001)/

The spin dependence of sp-derived bulk and surface states of fee-like Fe films on Cu(001) has been studied by spin-resolved inverse photoemi ssion. The exchange splitting of a crystal-induced surface state at (X ) over bar is determined as 0.9 eV. A transition between sp bulklike s tates about halfway between Gamma and (X) over bar shows a spin splitt ing of 0.4 eV. The first result is unique proof of a magnetically live surface layer. The latter shows that ferromagnetic order is not restr icted to the topmost layer, but the size of the splitting indicates th at the magnetic moment of the sublayers is reduced compared with the s urface.