Compressing nearly hard sphere fluids increases glass fragility

¹  Laboratoire des Colloïdes, Verres et Nanomatériaux, UMR 5587, Université Montpellier II and CNRS 34095 Montpellier, France, EU
²  James Franck Institute and Department of Physics, The University of Chicago - 929 E. 57th Street, Chicago, IL 60637, USA

Corresponding author: ludovic.berthier@lcvn.univ-montp2.fr

Received: 23 February 2009
Accepted: 11 March 2009

Abstract

We use molecular dynamics to investigate the glass transition occurring at large volume fraction, φ, and low temperature, T, in assemblies of soft repulsive particles. We find that equilibrium dynamics in the (φ, T)-plane obey a form of dynamic scaling in the proximity of a critical point at and , which should correspond to the ideal glass transition of hard spheres. This glass point, “point G", is distinct from athermal jamming thresholds. A remarkable consequence of scaling behaviour is that the dynamics at fixed φ passes smoothly from that of a strong glass to that of a very fragile glass as φ increases beyond . Correlations between fragility and various physical properties are explored.