The Dynamics of Silica Melts under High Pressure: Mode-Coupling Theory Results

Abstract

The high-pressure dynamics of a computer-modeled silica melt is studied in the framework of the mode-coupling theory of the glass transition (MCT) using static-structure input from molecular-dynamics (MD) computer simulation. The theory reproduces the experimentally known viscosity minimum (diffusivity maximum) as a function of density or pressure and explains it in terms of a corresponding minimum in its critical temperature. This minimum arises from a gradual change in the equilibrium static structure which shifts from being dominated by tetrahedral ordering to showing the cageing known from high-density liquids. The theory is in qualitative agreement with computer simulation results.

arXiv commentPresented at ESF EW Glassy Liquids under Pressure, to be published in Journal of Physics

References in corpus (10)

• Higher order glass-transition singularities in colloidal systems with attractive interactions
• Molecular structural order and anomalies in liquid silica
• Effect of Composition Changes on the Structural Relaxation of a Binary Mixture
• The Debye-Waller factor of liquid silica: Theory and simulation
• New fitting scheme to obtain effective potential from Car-Parrinello molecular dynamics simulations: Application to silica
• Slow Dynamics in Ion-Conducting Sodium Silicate Melts: Simulation and Mode-Coupling Theory
• Logarithmic Relaxation in a Colloidal System
• Revisiting the slow dynamics of a silica melt using Monte Carlo simulations
• Metastable phases and "metastable" phase diagrams
• Idealized glass transitions under pressure: dynamics versus thermodynamics

Cited by in corpus (4)

• The role of local structure in dynamical arrest
• Understanding, predicting, and tuning the fragility of vitrimeric polymers
• The Role of Intramolecular Barriers on the Glass Transition of Polymers: Computer Simulations vs. Mode Coupling Theory
• Many-body correlations are non-negligible in both fragile and strong glassformers