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

Title: Oxygen K-edge XANES of germanates investigated using first-principles calculations

Abstract

O K-edge x-ray absorption near-edge structure (XANES) spectra of {alpha}-quartz-type and rutile-type GeO{sub 2} polymorphs and of K{sub 2}Ge{sub 8}O{sub 17} have been analyzed using first-principles plane-wave pseudopotential calculations. XANES spectra have been calculated using supercell including core-hole effects and good agreement with experiment has been obtained. In the the case of GeO{sub 2} polymorphs, local density of empty states has been performed and peaks in the experimental spectra can be assigned to transitions involving hybridization of the O p orbitals with the Ge s, Ge p, Ge sp, and Ge d orbitals. Furthermore, peak positions in the theoretical spectra appear to be correlated with changes in the Ge-O-Ge angle as well as indirectly with the Ge coordination geometry. Analysis of O K-edge XANES spectra for individual O sites in K{sub 2}Ge{sub 8}O{sub 17} shows that oxygens shared between two fivefold Ge atoms or one fourfold and one fivefold Ge atom exhibit subtle shifts to lower energy of the peaks, which have been previously observed in alkali germanate glasses at and above the germanate anomaly.

Authors:
; ;  [1];  [2]
  1. Institut de Mineralogie et de Physique des Milieux Condenses, UMR CNRS 7590, Universite Pierre et Marie Curie, Paris 6, 140 rue de Lourmel, F-75015 Paris (France)
  2. (Canada)
Publication Date:
OSTI Identifier:
20951412
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 75; Journal Issue: 18; Other Information: DOI: 10.1103/PhysRevB.75.184205; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION; ABSORPTION SPECTRA; ABSORPTION SPECTROSCOPY; GERMANATES; GERMANIUM OXIDES; OXYGEN; PEAKS; POTASSIUM COMPOUNDS; QUARTZ; RUTILE; WAVE PROPAGATION; X RADIATION; X-RAY SPECTRA; X-RAY SPECTROSCOPY

Citation Formats

Cabaret, Delphine, Mauri, Francesco, Henderson, Grant S., and Department of Geology, University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1. Oxygen K-edge XANES of germanates investigated using first-principles calculations. United States: N. p., 2007. Web. doi:10.1103/PHYSREVB.75.184205.
Cabaret, Delphine, Mauri, Francesco, Henderson, Grant S., & Department of Geology, University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1. Oxygen K-edge XANES of germanates investigated using first-principles calculations. United States. doi:10.1103/PHYSREVB.75.184205.
Cabaret, Delphine, Mauri, Francesco, Henderson, Grant S., and Department of Geology, University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1. Tue . "Oxygen K-edge XANES of germanates investigated using first-principles calculations". United States. doi:10.1103/PHYSREVB.75.184205.
@article{osti_20951412,
title = {Oxygen K-edge XANES of germanates investigated using first-principles calculations},
author = {Cabaret, Delphine and Mauri, Francesco and Henderson, Grant S. and Department of Geology, University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1},
abstractNote = {O K-edge x-ray absorption near-edge structure (XANES) spectra of {alpha}-quartz-type and rutile-type GeO{sub 2} polymorphs and of K{sub 2}Ge{sub 8}O{sub 17} have been analyzed using first-principles plane-wave pseudopotential calculations. XANES spectra have been calculated using supercell including core-hole effects and good agreement with experiment has been obtained. In the the case of GeO{sub 2} polymorphs, local density of empty states has been performed and peaks in the experimental spectra can be assigned to transitions involving hybridization of the O p orbitals with the Ge s, Ge p, Ge sp, and Ge d orbitals. Furthermore, peak positions in the theoretical spectra appear to be correlated with changes in the Ge-O-Ge angle as well as indirectly with the Ge coordination geometry. Analysis of O K-edge XANES spectra for individual O sites in K{sub 2}Ge{sub 8}O{sub 17} shows that oxygens shared between two fivefold Ge atoms or one fourfold and one fivefold Ge atom exhibit subtle shifts to lower energy of the peaks, which have been previously observed in alkali germanate glasses at and above the germanate anomaly.},
doi = {10.1103/PHYSREVB.75.184205},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 18,
volume = 75,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}