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Title: Quantum size effects in the surface energy of Pb/Si(111) film nanostructures studied by surface x-ray diffraction and model calculations

Journal Article · · Physical Review. B, Condensed Matter and Materials Physics
; ;  [1];  [2]
  1. Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, Illinois 61801-3080 (United States)
  2. Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 S. Goodwin Avenue, Urbana, Illinois 61801-2902 (United States)

We have used surface x-ray diffraction from a synchrotron source, along with models based upon a free-electron gas confined to a quantum well, to study quantum size effects in the surface energy of ultrathin Pb films grown on pretreated Si(111) substrates. Films grown at 110 K are smooth, but as they are annealed to near room temperature, their morphology is observed evolving through various metastable states and eventually to a roughened state in local equilibrium. Strong variations in the stability of different island heights are observed, consistent with quasibilayer oscillations in the surface energy found from the theoretical free-electron calculations. By analyzing the quasiequilibrium distribution of thicknesses, empirical information on the film surface energy is obtained for a wide range of thicknesses. The morphological annealing behavior of the films is also found to be explained by the deduced surface energy.

OSTI ID:
20719336
Journal Information:
Physical Review. B, Condensed Matter and Materials Physics, Vol. 72, Issue 7; Other Information: DOI: 10.1103/PhysRevB.72.075402; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
Country of Publication:
United States
Language:
English