Striking role of non-bridging oxygen on glass transition temperature of calcium aluminosilicate glass-formers
M Bouhadja and N Jakse and A Pasturel, JOURNAL OF CHEMICAL PHYSICS, 140, 234507 (2014).
Molecular dynamics simulations are used to study the structural and dynamic properties of calcium aluminosilicate, (CaO- Al2O3)(1-x)(SiO2)(x), glass formers along three joins, namely, R = 1, 1.57, and 3, in which the silica content x can vary from 0 to 1. For all compositions, we determined the glass-transition temperature, the abundances of the non-bridging oxygen, triclusters, and AlO5 structural units, as well as the fragility from the temperature evolution of the alpha-relaxation times. We clearly evidence the role played by the non- bridging oxygen linked either to Al atoms or Si atoms in the evolution of the glass-transition temperature as well as of the fragility as a function of silica content along the three joins. (C) 2014 AIP Publishing LLC.
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