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arXiv · 0804.2130

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

Th. Voigtmann·J. Horbach
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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.

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Th. Voigtmann, J. Horbach. 2008-04-14. The Dynamics of Silica Melts under High Pressure: Mode-Coupling Theory Results. https://doi.org/10.1088/0953-8984%2F20%2F24%2F244117

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