Controlled creation of point defects in 3D colloidal crystals

Abstract

Crystal defects crucially influence the properties of crystalline materials and have been extensively studied. Even for the simplest type of defect - the point defect - however, basic properties such as their diffusive behavior, and their interactions, remain elusive on the atomic scale. Here we demonstrate in-situ control over the creation of isolated point defects in a 3D colloidal crystal allowing insight on a single particle level. Our system consists of thermoresponsive microgel particles embedded in a crystal of non-responsive colloids. Heating this mixed particle system triggers the shrinking of the embedded microgels, which then vacate their lattice positions creating vacancy-interstitial pairs. We use temperature-controlled confocal laser scanning microscopy to verify and visualize the formation of the point defects. In addition, by re-swelling the microgels we quantify the local lattice distortion around an interstitial defect. Our experimental model system provides a unique opportunity to shed new light on the interplay between point defects, on the mechanisms of their diffusion, on their interactions, and on collective dynamics.

arXiv comment15 pages, 9 figures

References in corpus (9)

• freud: A Software Suite for High Throughput Analysis of Particle Simulation Data
• Diffusion of Point Defects in Two-Dimensional Colloidal Crystals
• Equilibrium Configurations and Energetics of Point Defects in Two-Dimensional Colloidal Crystals
• An introduction to the colloidal glass transition
• Measuring nonlinear stresses generated by defects in 3D colloidal crystals
• Highly cooperative stress relaxation in two-dimensional soft colloidal crystals
• Self-organized defect strings in two-dimensional crystals
• Point Defects in Crystals of Charged Colloids
• Entropy and Kinetics of Point-Defects in Two-Dimensional Dipolar Crystals