April 1, 2017 at 10:45 pm

CMSS Colloquium | Universal Aging Dynamics of Silica, April 6

The Condensed Matter & Surface Sciences Colloquium Series presents Katharina Vollmayr-Lee of Bucknell University, on “Universal Aging Dynamics of Silica” on Thursday, April 20, at 4:10 p.m. in Walter 245.

Katharina Vollmayr-Lee

Katharina Vollmayr-Lee

Abstract: We investigate the non-equilibrium (aging) dynamics of the strong glass former  SiO2.  Using molecular dynamics simulations, we quench the system from high temperature to 2500 K, below the glass transition.  We analyze the dynamics both via single particle jumps, as well as via dynamic heterogeneities.

Since the system is out of equilibrium, we investigate the dependence of the dynamics on the waiting time, the time elapsed since the quench.  We find that both the dynamic susceptibility and the probability distribution of the local incoherent intermediate scattering function can be described by simple scaling forms in terms of the global incoherent intermediate scattering function.

When comparing our results for the strong glass former SiO2 to previous results for fragile glass formers, we find a striking similarity of both  the microscopic jump dynamics as well as the scaling of dynamic heterogeneities.

Furthermore we find for the scaling of dynamic heterogeneities that the aging dynamics is controlled by a unique aging clock which is the same for Si and O atoms.

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