Structure, Structural Relaxation and Ion Transport in Sodium Disilicate Melts

TL;DR

This study investigates the structure, relaxation dynamics, and ion transport in sodium disilicate melts using inelastic neutron scattering, revealing distinct relaxation times and temperature-dependent structural features.

Contribution

It provides new insights into the relaxation timescales and structural heterogeneity in sodium disilicate melts at high temperatures.

Findings

Na2SiO5 melts show Si-O network relaxation on nanosecond scale.

Na ion relaxation occurs on a 10 picosecond timescale.

A prepeak at ~0.9A-1 emerges more prominently with increasing temperature.

Abstract

We have investigated Na2SiO5 melts with inelastic neutron scattering at temperatures up to 1600K. The Si-O network relaxes on a time scale of ns, whereas the Na ion relaxation dynamics are found on a time scale of 10ps. The elastic structure factor exhibits at ~0.9A-1 an emerging prepeak which becomes more pronounced with increasing temperature. The prepeak is caused by the formation of sodium rich regions in the partially disrupted Si-O tetrahedral network.