Work Hardening in Colloidal Crystals

by Prof. Ilya Svetlizky

Department of Physics, Technion Israel Institute of Technology

at Biological and soft-matter physics

Thu, 01 Jan 2026, 12:10
Sacta-Rashi Building for Physics (54), room 207

Abstract

Colloidal crystals exhibit a rich behavior that is in many ways analogous to their atomic counterparts: they have the same crystal structures; they undergo the same phase transitions; and they possess the same crystallographic defects. In contrast to these structural properties, the mechanical properties of colloidal crystals are quite distinct from those of atomic systems. For example, unlike in atomic systems, the elasticity of hard-sphere colloidal crystals is purely entropic; as a result, they are so soft that they can be melted just by stirring. We use confocal microscopy to show that hard-sphere colloidal crystals exhibit work hardening, where they become stronger when subjected to increasing plastic deformation. Their strength increases with dislocation density, and, remarkably, ultimately follows the classic Taylor scaling behavior for atomic materials, even though hard-sphere interactions lack the complexity of atomic interactions. This striking resemblance between colloidal and atomic crystals, despite the many orders of magnitude difference in particle size and shear modulus, demonstrates the universality of work hardening.

Created on 08-10-2025 by Granek, Rony (rgranek)
Updaded on 27-12-2025 by Granek, Rony (rgranek)