A neutron scattering and nuclear magnetic resonance study of the structure of GeO2-P2O5 glasses.
Germanophosphate (GeO2-P2O5) glasses were studied with neutron diffraction, phosphorus, and oxygen nuclear magnetic resonance, calorimetry, viscosity measurements, and first-principles calculations. These data sets were combined to propose a structural model of GeO2-P2O5 glasses, which includes tetrahedrally coordinated phosphorus, formation of octahedrally coordinated germanium as P2O5 content increases, an absence of trigonally coordinated oxygen, and hence an absence of rutile-like GeO2 domains. The structural model was then used to propose explanations for both the observed composition dependence of the glass transition temperature and the fragility of the GeO2-P2O5 liquids.
Zwanziger
J W
JW
Department of Chemistry and Institute for Research in Materials, Dalhousie University, Halifax, NS, Canada. jzwanzig@dal.ca
Shaw
J L
JL
Werner-Zwanziger
U
U
Aitken
B G
BG