4 January, 2010

What is there to be explained about glasses and glassformers?  Facts, questions, views

Part 1

Part 2

Abstract

In my first lecture I discuss glasses, glassformers and glass formation. I first address the question of what is meant by a "glass" or a "glassy" system? I introduce commonly invoked properties to characterize such systems: jammed/arrested/solid-like state, disordered state, out-of-equilibrium state. I briefly describe and tentatively classify the variety of glasses.

I then consider ways of forming glassy states. Focusing next on the "standard glasses" formed by cooling from a liquid or a melt, I stress the diversity of questions and of views, which depend on the temperature regime of interest; with increasing temperature: low-T (cryogenic) anomalous properties of glasses; aging and nonlinear rheology in glasses; transformation region; supercooled liquid, viscous slowing down and glass transition; avoidance of crystallization. Finally I discuss the possible control parameters for glass formation and the notion of jamming.

In my next lecture, I specialize my presentation to supercooled liquids and the glass transition. I describe the salient properties of supercooled liquids. What is there to be explained ? Again, I will stress the diversity of views. I then discuss a selection (my selection) of questions concerning the slowing down of relaxation that lead to glass formation.

 

References and suggested reading

  1. Collection of overviews (Tarjus-Kivelson on supercooled liquids, Durian-Liu on colloidal suspensions, Kurchan on aging and rheology,...) in Jamming and Rheology, A. J. Liu and S.R. Nagel Eds (Taylor and Francis, London, 2001).
  2. M.D. Ediger, C. A. Angell and R. Nagel, Supercooled liquids and glasses, J. Phys. Chem 100, 13200 (1996).
  3. S. A. Kivelson and G. Tarjus, In search of a theory of supercooled liquids, Nature materials 7, 831 (2008).
  4. L. Berthier and G. Biroli, Glasses and aging: A statistical Mechanics perspective, Encyclopedia of Complexity and Systems Science, 2009 (available from Ludovic Berthier webpage).
  5. Collection of overviews in Slow relaxations and nonequilibrium dynamics in condensed matter, J.-L. Barrat et al. Eds. (EDP Sciences- Springer Verlag, 2003).