Nanoscopic Study of the Ion Dynamics in a LiAlSiO$_4$ Glass Ceramic by means of Electrostatic Force Spectroscopy

TL;DR

This study employs electrostatic force spectroscopy to analyze ion dynamics in LiAlSiO$_4$ glass ceramics, revealing two distinct relaxation processes associated with different structural regions, and compares these microscopic insights with macroscopic conductivity data.

Contribution

It introduces the use of time-domain electrostatic force spectroscopy to distinguish ion relaxation processes in glass ceramics, providing nanoscale insights beyond traditional macroscopic measurements.

Findings

Two relaxation processes with different activation energies identified.

Faster process linked to glassy phase and interfaces.

Slower process associated with crystallite ion movements.

Abstract

We use time-domain electrostatic force spectroscopy (TD-EFS) for characterising the dynamics of mobile ions in a partially crystallised LiAlSiO$_4$ glass ceramic, and we compare the results of the TD-EFS measurements to macroscopic electrical conductivity measurements. While the macroscopic conductivity spectra are determined by a single dynamic process with an activation energy of 0.72 eV, the TD-EFS measurements provide information about two distinct relaxation processes with different activation energies. Our results indicate that the faster process is due to ionic movements in the glassy phase and at the glass-crystal interfaces, while the slower process is caused by ionic movements in the crystallites. The spatially varying electrical relaxation strengths of the fast and of the slow process provide information about the nano- and mesoscale structure of the glass ceramic.