Effect of stress wave irradiation on structural change in a colloidal system

Abstract

Annealing is a typical method for controlling crystallographic structure of solids, and by increasing the number of phonon modes by heating, structural changes are caused. Considering that stress waves also enhance lattice vibrations, stress-wave irradiation should have similar effect on structural changes. In this study, we investigate the effect of stress-wave irradiation on crystallization of an amorphous solid using a colloidal system. A colloidal system used in this study is a mixture of a solution dyed with a fluorescein sodium salt and silica particles. It shows phases similar to those of atomic systems, and ordered (crystalline) and disordered (amorphous) structures are obtained. Because particle-scale analysis can be performed by using the confocal laser scanning microscopy, it has been used as a model system of atomic materials. We evaluate structural change of a colloidal glass after stress-wave irradiation and find that crystallization is accelerated at a specific condition. In the presentation, details of the results are described, and its origin is discussed.