Melting of Two-Dimensional Colloidal Crystals - Microscopic Understanding of Hexatics and Dense Fluids
20 October 1988
We have observed a two-step melting transition in a two dimensional system with classical screened Coulomb interactions. We use optical microscopy and digital imaging to investigate the real space and real time behavior of an ultraclean colloidal suspension of highly charged, submicron sized spheres confined into two dimensions between two smooth glass plates. The experimental system has a lateral extent of at least 1000 spheres and has been allowed to equilibrate for over 10 sup 5 time steps. Direct observation of topological defects and computed correlation functions from real space images give insight into the nature of two dimensional melting in this system.