skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Surface x-ray-diffraction study and quantum well analysis of the growth and atomic-layer structure of ultrathin Pb/Si(111) films

Abstract

We present surface x-ray-diffraction results from Pb films grown on pretreated Si(111) substrates at 110 K. Time-resolved data show that the films follow a metastable layer-by-layer growth mode. The resulting film roughness is small, allowing for a thickness-dependent study of the film layer structure and its distortion (strain) relative to the bulk. The strain arises as a result of quantum confinement of the electrons in the film, which leads to charge distortions similar to Friedel oscillations. The charge distortions in turn lead to lattice distortions, for which two models are derived based on a free-electron gas confined to a quantum well. Extended x-ray-reflectivity data show evidence of quasibilayer distortions in the film, which are well described by the free-electron models. Oscillations in the relaxations of the Pb layers closest to the film boundaries as a function of thickness are also observed. Calculations of the net expansion or contraction of the films as a function of thickness are made that also exhibit quasibilayer variations and are consistent with the results of previous studies.

Authors:
; ;  [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)
Publication Date:
OSTI Identifier:
20719146
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 72; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevB.72.035305; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ELECTRON GAS; ELECTRONS; INTERFACES; LAYERS; LEAD; PLATINUM; QUANTUM WELLS; REFLECTION; REFLECTIVITY; RELAXATION; ROUGHNESS; STRAINS; STRESSES; SUBSTRATES; SURFACES; THICKNESS; THIN FILMS; TIME RESOLUTION; X-RAY DIFFRACTION

Citation Formats

Czoschke, P, Basile, L, Chiang, T -C, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 S. Goodwin Avenue, Urbana, Illinois 61801-2902, and Hong, Hawoong. Surface x-ray-diffraction study and quantum well analysis of the growth and atomic-layer structure of ultrathin Pb/Si(111) films. United States: N. p., 2005. Web. doi:10.1103/PhysRevB.72.035305.
Czoschke, P, Basile, L, Chiang, T -C, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 S. Goodwin Avenue, Urbana, Illinois 61801-2902, & Hong, Hawoong. Surface x-ray-diffraction study and quantum well analysis of the growth and atomic-layer structure of ultrathin Pb/Si(111) films. United States. doi:10.1103/PhysRevB.72.035305.
Czoschke, P, Basile, L, Chiang, T -C, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 S. Goodwin Avenue, Urbana, Illinois 61801-2902, and Hong, Hawoong. Fri . "Surface x-ray-diffraction study and quantum well analysis of the growth and atomic-layer structure of ultrathin Pb/Si(111) films". United States. doi:10.1103/PhysRevB.72.035305.
@article{osti_20719146,
title = {Surface x-ray-diffraction study and quantum well analysis of the growth and atomic-layer structure of ultrathin Pb/Si(111) films},
author = {Czoschke, P and Basile, L and Chiang, T -C and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 S. Goodwin Avenue, Urbana, Illinois 61801-2902 and Hong, Hawoong},
abstractNote = {We present surface x-ray-diffraction results from Pb films grown on pretreated Si(111) substrates at 110 K. Time-resolved data show that the films follow a metastable layer-by-layer growth mode. The resulting film roughness is small, allowing for a thickness-dependent study of the film layer structure and its distortion (strain) relative to the bulk. The strain arises as a result of quantum confinement of the electrons in the film, which leads to charge distortions similar to Friedel oscillations. The charge distortions in turn lead to lattice distortions, for which two models are derived based on a free-electron gas confined to a quantum well. Extended x-ray-reflectivity data show evidence of quasibilayer distortions in the film, which are well described by the free-electron models. Oscillations in the relaxations of the Pb layers closest to the film boundaries as a function of thickness are also observed. Calculations of the net expansion or contraction of the films as a function of thickness are made that also exhibit quasibilayer variations and are consistent with the results of previous studies.},
doi = {10.1103/PhysRevB.72.035305},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 3,
volume = 72,
place = {United States},
year = {2005},
month = {7}
}