Fe on Au(100): Quantum-well states down to a monolayer

Quantum-well states are observed for Fe films embedded in Au(100) using inverse photoemission. They can be analyzed with a simple interferometer model, using bulk states from the 12 1H15 band that are modulated by an envelope function with wavelengths in the order of 7 10 atomic layers (10 14). These states can be followed down to a monolayer, where two states are seen at 0.6 and 1.9 eV. They are tentatively assigned to the 5 monolayer state and a 1 quantum-well state. The resulting ferromagnetic exchange splitting of the 5 is 2.7 eV, exceeding the splitting of 1.8 2.1 eV for the analogous bulk band. © 1991 The American Physical Society.