Structural organisation in oxide glasses from molecular dynamics modelling

Mountjoy, G. and Al-Hasni, B.M. and Storey, C. (2011) Structural organisation in oxide glasses from molecular dynamics modelling. Journal of Non-Crystalline Solids, 357 (14). pp. 2522-2529. ISSN 00223093 (ISSN). (doi:https://doi.org/10.1016/j.jnoncrysol.2011.01.015) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Abstract

Classical molecular dynamics modelling has been used to obtain new models of 50CaO�50P2O5 and 50MgO�50SiO2 glasses and, together with previously published models of 63CaO�37Al 2O3, and 50CaO�50SiO2 glasses, these have been inspected to evaluate structural features. For the first time, models of glasses near the eutectic in three systems, aluminate, silicate, and phosphate, with the same modifier, Ca, have been compared. All have short range order which is similar to that in crystals of the same composition, 5CaO�3Al 2O3, CaSiO3 and Ca(PO3)2. There is a clear trend in bonding of bridging oxygen to Ca, which is dominant in aluminate glass, common in silicate glass, and absent in phosphate glass. Preliminary results for 50MgO�50SiO2 glass show unusual behaviour because � 5% of oxygen is present as "non-network" oxygen, i.e. bonded only to Mg. The models show broader Qn distributions than seen in NMR experiments, and this remains an area for improvement of MD modelling of glasses. The distributions of Ca in the models have been studied using the pair distribution function TCaCa(r) which is found to be similar in the three glasses, and also similar to the previous experimental measurement for 50CaO�50SiO2 glass. The distributions of Ca are markedly different in the glasses compared to the crystals, being isotropic in the former and anisotropic in the latter, which should be a factor in glass forming ability. © 2011 Elsevier B.V. All rights reserved.

Item Type: Article
Additional information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - J Non Cryst Solids [Field not mapped to EPrints] AD - School of Physical Sciences, University of Kent, Canterbury, United Kingdom [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints]
Uncontrolled keywords: Medium range order, Molecular dynamics, Phosphate glasses, Silicate glasses, Aluminate glass, Bridging oxygen, Classical molecular dynamics, Experimental measurements, Glass forming ability, Medium range order, New model, Oxide glass, Pair distribution functions, Phosphate glass, Phosphate glasses, Short range orders, Silicate glass, Silicate glasses, Structural feature, Three systems, Calcium, Crystals, Distribution functions, Glass bonding, Molecular dynamics, Nuclear magnetic resonance spectroscopy, Oxygen, Silicates, Glass
Subjects: Q Science > QC Physics > QC176 Solid state physics
Q Science
Q Science > QC Physics
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Giles Tarver
Date Deposited: 16 Jan 2015 09:36 UTC
Last Modified: 27 Feb 2015 10:28 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/46597 (The current URI for this page, for reference purposes)
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