Non-equilbrium Dynamics in Amorphous Si_3B_3N_7

Abstract

We present extensive numerical investigations of the structural relaxation dynamics of a realistic model of the amorphous high-temperature ceramic a-Si${}_3$B${}_3$N${}_7$, probing the mean square displacement (MSD) of the atoms, the bond survival probability (BSP), the average energy, the specific heat, and the two-point energy average. Combining the information from these different sources, we identify a transition temperature $T_c\approx 2000$ K below which the system is no longer ergodic and physical quantities observed over a time $t_{obs}$ show a systematic parametric dependence on the waiting time $t_w$, or age, elapsed after the quench. The aging dynamics 'stiffens' as the system becomes older, which is similar to the behavior of highly idealized models such as Ising spin-glasses and Lennard-Jones glasses.

Journal of Phys. Chem.B in press.Extended version of paper cond-mat/0212245