Regensburg 2004 – wissenschaftliches Programm
O 11.6: Vortrag
Montag, 8. März 2004, 17:00–17:15, H44
Quantum well states and their influence on layer restructuring in Pb/Cu(111) — •Hugo Dil1, JeongWon Kim1, Shubha Gokhale2 und Karsten Horn1 — 1Fritz-Haber-Institut der MPG, 14195 Berlin — 2Indira Gandhi National Open University, New Delhi, India
Quantum well states in thin metal films, arising from one-dimensional confinement of the conduction electrons, may have a profound influence on their physical properties. Quantum well states may induce preferred magic heights in thin film growth, and this has been observed several systems. We have studied the electronic structure of Pb layers on Cu(111) grown under different conditions, using angle-resolved photoelectron spectroscopy. Our results for Pb films deposited at 100 K show a series of well-resolved peaks in the s-p-derived valence band near the Fermi level, the energy and intensity of which evolve in a complex manner with Pb deposition. These data are analysed in terms of the phase accumulation model, shown to account for quantum well states in a large number of systems. Upon annealing, the layers undergo a restructuring, and preferred layer height emerge as shown by their quantum well spectrum signature. We interpret this process in terms of electronic energy minimization.