Regensburg 2002 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 42: Statistische Physik fernab vom Gleichgewicht I

DY 42.2: Vortrag

Donnerstag, 14. März 2002, 11:30–11:45, H2

Aging behaviour in a-Si₃B₃N₇ - an energy landscape approach — •J. Christian Schön, Alexander Hannemann, and Martin Jansen — Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1,70569 Stuttgart

We study the aging behaviour of amorphous Si₃B₃N₇ in the non-ergodic regime using Monte-Carlo simulations in the NVT-ensemble. In the investigated system a transition from ergodic to non-ergodic behaviour occurs at T_t≈ 2000K, close to the experimentally observed decomposition temperature. We interpretate our results in terms of an energy landscape picture. We find a non-exponential decay of the potential energy with a temperature dependent decay parameter. Additionally we find waiting time t_w and observation time t_obs dependences for the calculated mean energies and the calculated fluctuations, clearly showing the breakdown of the fluctuation-dissipation theorem for long observation times t_obs ≥ t_w. The structural properties of the investigated structural model are in agreement with experimental findings.