Layer-by-layer resolved core-level shifts inCaF2andSrF2on Si(111): Theory and experiment

Autor:	Marjorie A. Olmstead, Jonathan D. Denlinger, Eli Rotenberg, M. Leskovar, Uwe Hessinger
Rok vydání:	1994
Předmět:	symbols.namesake Tetragonal crystal system Materials science Auger effect Astrophysics::High Energy Astrophysical Phenomena Layer by layer symbols Emission spectrum Thin film Spectroscopy Molecular physics Electron spectroscopy Spectral line
Zdroj:	Physical Review B. 50:11052-11069
ISSN:	1095-3795 0163-1829
DOI:	10.1103/physrevb.50.11052
Popis:	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.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::b48062555f109787742a53bb8755e0c5 https://doi.org/10.1103/physrevb.50.11052 Zobrazit plný text záznamu