Ion dynamics computer simulations of BeF2 were carried out over a temperature range which overlapped with the experimental viscosity data. Diffusivity data was obtained using the simple rigid ion potentials. A highly anomalous region of behavior was shown by the diffusivity data at temperatures just above the limits of laboratory measurement, which reconciled the observed viscosity with that of other liquids. Interpretion of this strongly curved region was done in terms of a strongly negative liquid expansivity regime associated with a large heat capacity regime using the Adams-Gibbs equation. The fragility of the BeF2 and SiO2 was shown to greatly exceed that of Lennard-Jones liquids.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry