Session L27: Glassy Systems
2:30 PM–5:06 PM, Tuesday, March 6, 2007
Colorado Convention Center Room: 301
Sponsoring Unit:
DCMP
Chair: Dimitrios Papaconstantopoulos, George Mason University
Abstract ID: BAPS.2007.MAR.L27.10
Abstract: L27.00010 : Locations of metal ions in the new glasses in the alumina-calcia-monazite (LaPO$_{4})$ system
4:18 PM–4:30 PM
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Abstract 
Authors:
Robert Marzke
(Arizona State University)
George Wolf
(Arizona State University)
Susan Boucher
(Arizona State University)
Jeremy Piwowarczyk
(Arizona State University)
William Petuskey
(Arizona State University)
The new group of glasses synthesized from calcium aluminate (CaAl$_{2}$O$_{4})$ or C12A7 (CaO)$_{12}$(Al$_{2}$O$_{3})_{7}$ with varying fractions of La-monazite (LaPO$_{4})$ has been characterized by electron microscopy, $^{31}$P and $^{27}$Al NMR, Raman scattering and chemical methods. These techniques have yielded information concerning the environments of the metal ions Al and La in the glasses. A substantial negative shift of the principal $^{31}$P NMR line at all monazite fractions, along with Raman spectra showing that PO$_{4}$ groups do not share bridging oxygens, places La within the second coordination shell surrounding P. P-Al TRAPDOR double NMR experiments show that aluminum and phosphorus are also closely coordinated, accounting for a second, more negatively shifted line in the $^{31}$P single resonance spectra. Models for the structures of these glasses have been constructed for a range of monazite contents, and will be presented.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.MAR.L27.10