Layer-by-layer resolved core-level shifts in CaF[sub 2] and SrF[sub 2] on Si(111): Theory and experiment

Journal Article · Sat Oct 15 04:00:00 EDT 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.50.11052· OSTI ID:7180526

Rotenberg, E ^[1]; Denlinger, J D ^[2]; Leskovar, M; Hessinger, U; Olmstead, M A ^[3]

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1. Department of Physics, University of California, Berkeley, California 94720 (United States)
2. Department of Physics, University of Wisconsin, Milwaukee, Wisconsin 53211 (United States)
3. Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)

Using x-ray-photoelectron spectroscopy and Auger-electron spectroscopy, we have resolved surface, bulk, and interface Ca and F core-level emission in thin films (3--8 triple layers) of CaF[sub 2] and SrF[sub 2] on Si(111). We confirmed these assignments using x-ray-photoelectron diffraction (XPD) and surface modification. XPD was also used to identify the growth modes of the films as being either laminar or layer plus islands; in the latter case we have resolved buried and uncovered interface F and Ca/Sr emission. We compare the observed energy differences between surface, bulk, and interface emission to theoretical estimates of the extra-atomic contributions to emission energies. We find excellent agreement considering only the Madelung (electrostatic) potentials for the initial-state contribution and polarization response for the final-state contribution, including the effect of tetragonal strain. Small discrepancies for emission from metal atoms bonded to the Si substrate are interpreted in terms of chemical shifts.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7180526
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:15; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
AUGER EFFECT
CALCIUM COMPOUNDS
CALCIUM FLUORIDES
CALCIUM HALIDES
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
EMISSION SPECTRA
FILMS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INTERFACES
IONIZING RADIATIONS
PHOTOELECTRON SPECTROSCOPY
RADIATIONS
SPECTRA
SPECTROSCOPY
STRONTIUM COMPOUNDS
STRONTIUM FLUORIDES
SURFACE PROPERTIES
THIN FILMS
X RADIATION