Skip to main content
Article
An EXAFS Investigation of Rare-Earth Local Environment in Ultraphosphate Glasses
Journal of Non-Crystalline Solids
  • Andrew K. Wittenauer
  • Richard K. Brow, Missouri University of Science and Technology
  • Mevlüt Karabulut
  • Ezz Metwalli
  • G. K. Marasinghe
  • C. H. Booth
  • J. J. Bucher
  • D. K. Shuh
Abstract

The local structures around rare-earth ions in rare-earth ultraphosphate glasses (nominally 15RE2O3-85P2O5, mol%, RE = Nd, Sm, Gd, Ho, and Er) and metaphosphate glasses (nominally 25RE2O3-75P2O5, mol%, RE = Nd, Gd, and Er) have been studied by extended X-ray absorption fine structure spectroscopy (EXAFS) at the respective rare-earth LIII edges. The RE-O distance decreases with increasing atomic number of the rare-earth ion for both ultra and metaphosphate glasses. On average, RE-O distances for metaphosphate glasses are shorter than those for ultraphosphate glasses of comparable compositions. There are 7-8 oxygen nearest neighbors in the first co-ordination sphere around rare-earth ions in ultraphosphate glasses and not, vert, similar6 oxygens in the first co-ordination sphere around rare-earth ions in metaphosphate glasses. There is no systematic dependence of the RE-O co-ordination number on the atomic number of the rare-earth ions in either compositional series. The second co-ordination shell around rare-earth ions in ultraphosphate glasses consists of phosphorus ions for all but the samarium ultraphosphate glass, with a RE-P distance between 3.53 and 3.85 Å and co-ordination numbers between 3 and 5. No RE-RE correlations were found within a distance of 4.5 Å.

Department(s)
Materials Science and Engineering
Keywords and Phrases
  • EXAFS,
  • Rare-Earth Local Environment,
  • Ultraphosphate Glass
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2005 Elsevier Inc., All rights reserved.
Publication Date
1-1-2005
Publication Date
01 Jan 2005
Citation Information
Andrew K. Wittenauer, Richard K. Brow, Mevlüt Karabulut, Ezz Metwalli, et al.. "An EXAFS Investigation of Rare-Earth Local Environment in Ultraphosphate Glasses" Journal of Non-Crystalline Solids (2005) ISSN: 0022-3093; 1873-4812
Available at: http://works.bepress.com/richard-brow/6/