Understanding liquids and glass transition on the basis of elastic interactions

Add to your list(s) Download to your calendar using vCal

• Kostya Trachenko
• Monday 02 February 2009, 16:00-17:00
• Harker 2 lecture room, Department of Earth Sciences, Downing Site.

If you have a question about this talk, please contact Ian Farnan.

Existing textbook expressions for the energy and heat capacity of gases and solids are widely taught in physics courses. However, no such expression exists for a liquid. Based on the old idea of Frenkel, I formulate this problem in the language of phonons, and calculate liquid energy and heat capacity for both the classical and quantum cases.

I subsequently address the old and very controversial problem of glass transition, and propose the solution that is based on elastic interactions in a liquid. Central to this discussion is the range of propagation of high-frequency elastic waves in a liquid, which I call “liquid elasticity length d”. d measures the range over which local relaxation events in a liquid elastically interact with each other via the elastic waves they induce. d is small at high temperature, and increases on lowering the temperature. This sets the cooperativity of molecular relaxation in a liquid, and gives the famous Vogel-Fulcher-Tammann law. In this picture, I also discuss other central properties of glass transition: the absence of divergence at a finite temperature, the origins of two dynamic crossovers and the origin of liquid “fragility” (Angell plot).

This talk is part of the Mineral Sciences Seminars series.

This talk is included in these lists:

• Department of Earth Sciences seminars
• Harker 2 lecture room, Department of Earth Sciences, Downing Site
• Mineral Sciences Seminars

Note that ex-directory lists are not shown.