Angle-resolved photoemission from atomically uniform silver films on iron (100) shows quantum-well states for absolutely determined film thicknesses ranging from 1 to approximately 100 monolayers. These states can be understood in terms of Fabry-Perot modes in an electron interferometer. A quantitative line shape analysis over the entire two orders of magnitude of thickness range yields an accurate measurement of the band structure, quasiparticle lifetime, electron reflectivity, and phase shift. Effects of confinement energy gap, reflection loss, and surface scattering caused by controlled roughness are demonstrated.

The strength of electron-phonon coupling in atomically uniform films of Ag on Fe is determined by angle-resolved photoemission from quantum well states in these films over a wide temperature range. As the film thickness is reduced, contributions from the surface and interface should become more important, and, experimentally, a large enhancement with superimposed quantum oscillations is observed. An analysis of the quantum oscillations indicates that this large enhancement is an interface effect.

We have studied the structural stability of thin silver films with thicknesses of N = 1 to 15 monolayers, deposited on an Fe(100) substrate. Photoemission spectroscopy results show that films of N = 1, 2, and 5 monolayer thicknesses are structurally stable for temperatures above 800 kelvin, whereas films of other thicknesses are unstable and bifurcate into a film with N +/- 1 monolayer thicknesses at temperatures around 400 kelvin. The results are in agreement with theoretical predictions that consider the electronic energy of the quantum well associated with a particular film thickness as a significant contribution to the film stability.

Observations of d-band quantum well states are made for atomically uniform Ag films on Fe(100) using angle-resolved photoemission. For increasing film thicknesses, quantum well peaks within the small 4d bandwidth multiply rapidly and merge into a bulklike spectrum at approximately 25 monolayers. An analysis of the peak positions yields a highly accurate bulk band structure of Ag. A very narrow d-band peak width (13 meV) is observed at the band top.