Non-equilbrium Dynamics in Amorphous Si_3B_3N_7

TL;DR

This paper investigates the non-equilibrium relaxation dynamics of amorphous Si3B3N7, revealing a transition temperature below which the system exhibits aging and non-ergodic behavior similar to spin-glasses and glasses.

Contribution

It provides a detailed numerical analysis of structural relaxation and aging phenomena in amorphous Si3B3N7, identifying a critical temperature for ergodicity breaking.

Findings

Transition temperature T_c ≈ 2000 K identified

System exhibits aging and non-ergodic behavior below T_c

Relaxation dynamics resemble spin-glass and glass models

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.