Shear-Induced Melting

Abstract

The collective translational structure of dilute suspensions (∼ 0.1% by weight) of charged, spherical, and colloidal particles under shear is investigated by light scattering. When subjected to increasing shear rate, the equilibrium bcc Wigner lattice exhibits two major, reversible, disordering transitions. Transition II occurs at low shear, is kink mediated and results in freely slipping two-dimensional hcp layers. At higher rates, transition I occurs where these two-dimensional layers melt via shear-induced fluctuations (phonons) to produce an amorphous structure. The amorphous structure has stringlike particle correlations which ultimately disappear.