Fragmentation and Limits to Dynamical Scaling in Viscous Coarsening: An Interrupted in situ X-Ray Tomographic Study

TL;DR

This study uses in situ X-ray microtomography to investigate phase separation and coarsening in a viscous silicate glass, revealing a linear growth law and partial breakdown of dynamical scaling due to fragmentation.

Contribution

It provides the first detailed 3D morphological analysis of viscous coarsening in a ternary glass, highlighting fragmentation effects on scaling behavior.

Findings

Linear growth law of domain size ($\, \, \, \, t$) observed.

Dynamical scaling holds for most geometrical observables.

Fragmentation causes departure from local curvature distribution scaling.

Abstract

X-Ray microtomography was used to follow the coarsening of the structure of a ternary silicate glass experiencing phase separation in the liquid state. The volumes, surfaces, mean and Gaussian curvatures of the domains of minority phase were measured after reconstruction of the 3D images and segmentation. A linear growth law of the characteristic length scale $\ell \sim t$ was observed. A detailed morphological study was performed. While dynamical scaling holds for most of the geometrical observables under study, a progressive departure from scaling invariance of the distributions of local curvatures was evidenced. The latter results from a gradual fragmentation of the structure in the less viscous phase that also leads to a power-law size distribution of isolated domains.