skip to main content

SciTech ConnectSciTech Connect

Title: An extended topological model for binary phosphate glasses

We present a topological model for binary phosphate glasses that builds on the previously introduced concepts of the modifying ion sub-network and the strength of modifier constraints. The validity of the model is confirmed by the correct prediction of T{sub g}(x) for covalent polyphosphoric acids where the model reduces to classical constraint counting. The constraints on the modifying cations are linear constraints to first neighbor non-bridging oxygens, and all angular constraints are broken as expected for ionic bonding. For small modifying cations, such as Li{sup +}, the linear constraints are almost fully intact, but for larger ions, a significant fraction is broken. By accounting for the fraction of intact modifying ion related constraints, q{sub γ}, the T{sub g}(x) of alkali phosphate glasses is predicted. By examining alkali, alkaline earth, and rare earth metaphosphate glasses, we find that the effective number of intact constraints per modifying cation is linearly related to the charge-to-distance ratio of the modifying cation to oxygen.
Authors:
 [1] ; ;  [2] ;  [1] ;  [3]
  1. Section of Chemistry, Aalborg University, 9220 Aalborg (Denmark)
  2. Otto Schott Institute of Materials Research, University of Jena, 07743 Jena (Germany)
  3. (China)
Publication Date:
OSTI Identifier:
22415431
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CATIONS; COVALENCE; LIMITING VALUES; LITHIUM IONS; OXYGEN; PHOSPHATE GLASS; PHOSPHATES; RARE EARTH COMPOUNDS