Aging in the glass former $B_{2}O_{3}$: A dynamic light scattering study.

Dallari F., Monti M., Monaco G.
  Lunedì 11/09   14:30 - 18:30   Aula A224   II - Fisica della materia
The aging properties of the glass former $B_{2}O_{3}$ have been studied in the glass transition temperature region using dynamic light scattering with a multispeckle setup, allowing us to obtain reliable autocorrelation functions for relaxation times ($\tau$) up to $10^{4}$ seconds. During aging, the autocorrelation function can be described with a stretched exponential only at times smaller than $\tau$, and overall it has to be described with a more complex functional form. Equilibrium is reached only for waiting times longer than about $10\tau$. Only at equilibrium the autocorrelation function regains the stretched exponential shape characteristic of the undercooled liquid.