Dissipation by a crystallization process

¹ Physics and Materials Science Research Unit, Université du Luxembourg - L-1511 Luxembourg, Luxembourg
² Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR) - D-51170 Köln, Germany
³ Department of Physics, Heinrich-Heine-Universität Düsseldorf - D-40225 Düsseldorf, Germany

Received: 12 October 2015
Accepted: 8 January 2016

Abstract

We discuss crystallization as a non-equilibrium process. In a system of hard spheres under compression at a constant rate, we quantify the amount of heat that is dissipated during the crystallization process. We interpret the dissipation as arising from the resistance of the system against phase transformation. An intrinsic compression rate is identified that separates a quasi-static regime from one of rapidly driven crystallization. In the latter regime the system crystallizes more easily, because new relaxation channels are opened, at the cost of forming a higher fraction of non-equilibrium crystal structures. We rationalize the change in the crystallization mechanism by analogy with shear thinning, in terms of a kinetic competition between near-equilibrium relaxation and external driving.