Starts 4 Jun 2008 12:00
Ends 4 Jun 2008 20:00
Central European Time
Leonardo da Vinci Building Seminar Room
Strada Costiera, 11 I - 34151 Trieste (Italy)
The relationship between dynamics, a growing length scale associated with cooperatively rearranging regions, and configurational entropy underlie the Adam-Gibbs theory of dynamics in glass forming liquids. While the Adam-Gibbs relation between relaxation times and configurational entropy has been widely employed to rationalize experimental and computer simulation data, attempts to directly study the length scales associated with cooperatively rearranging regions have been relatively few. Fresh impetus in this direction comes from recent studies of spatially heterogeneous dynamics, wherein analysis of spatial correlations of the mobility of particles allows estimation of a dynamical length. Finite size scaling is employed in the present work to evaluate a dynamical length scale in a model glass forming liquid, whose relationship to relaxation times and configurational entropy are examined. Comparison with theoretical predictions reveal partial agreement, and yield surprises that require further theoretical analysis to resolve. The configurational entropy is found to determine relaxation times for all temperatures and system sizes studied through the Adam-Gibbs relation, but the configurational entropy of cooperatively rearranging regions grows as the temperature is lowered, contrary to the assumptions of Adam-Gibbs theory.
  • M. Poropat