Composition dependence of glass transition temperature and fragility. II. A topological model of alkali borate liquids

John C. Mauro, Prabhat K. Gupta, Roger J. Loucks

doi:10.1063/1.3152432

Composition dependence of glass transition temperature and fragility. II. A topological model of alkali borate liquids

John C. Mauro

Corning Incorporated 1 Science and Technology Division, , Corning, New York 14831, USA
Prabhat K. Gupta

Ohio State University 2 Department of Materials Science and Engineering, , Columbus, Ohio 43210, USA
Roger J. Loucks

Alfred University 3 Department of Physics and Astronomy, , Alfred, New York 14802, USA

説明

<jats:p>Glass transition temperature and fragility are two important properties derived from the temperature dependence of the shear viscosity of glass-forming melts. While direct calculation of these properties from atomistic simulations is currently infeasible, we have developed a new topological modeling approach that enables accurate prediction of the scaling of both glass transition temperature and fragility with composition. A key feature of our approach is the incorporation of temperature-dependent constraints that become rigid as a liquid is cooled. Using this approach, we derive analytical expressions for the composition (x) dependence of glass transition temperature, Tg(x), and fragility, m(x), in binary alkali borate systems. Results for sodium borate and lithium borate systems are in agreement with published values of Tg(x) and m(x). Our modeling approach reveals a natural explanation for the presence of the constant Tg regime observed in alkali borate systems.</jats:p>