Ergodicity breaking in strong and network-forming glassy system

TL;DR

This study investigates the temperature-dependent non-ergodicity factor in vitreous GeO$_2$, revealing behavior consistent with Mode Coupling Theory and supporting the existence of an ergodic to non-ergodic transition in strong, network-forming glasses.

Contribution

It provides experimental evidence of ergodicity breaking in a strong, network-forming glass, extending Mode Coupling Theory predictions to such systems.

Findings

Non-ergodicity factor follows Mode Coupling Theory predictions.

Evidence of ergodic to non-ergodic transition in vitreous GeO$_2$.

Behavior observed across glassy and undercooled liquid states.

Abstract

The temperature dependence of the non-ergodicity factor of vitreous GeO$_2$, $f_{q}(T)$, as deduced from elastic and quasi-elastic neutron scattering experiments, is analyzed. The data are collected in a wide range of temperatures from the glassy phase, up to the glass transition temperature, and well above into the undercooled liquid state. Notwithstanding the investigated system is classified as prototype of strong glass, it is found that the temperature- and the $q$-behavior of $f_{q}(T)$ follow some of the predictions of Mode Coupling Theory. The experimental data support the hypothesis of the existence of an ergodic to non-ergodic transition occurring also in network forming glassy systems.