Jamming, relaxation and crystallization of a super-cooled fluid in a three-dimensional lattice

TL;DR

This study investigates the off-equilibrium dynamics of a 3D lattice model, revealing how amorphous structures evolve and relax towards crystallization, highlighting deviations from classical nucleation theory.

Contribution

It introduces a detailed analysis of non-equilibrium filling and relaxation processes in a 3D lattice model, showing new mechanisms for crystallization beyond classical theories.

Findings

Disordered states reach random closest packing density within the solid regime.

Two power-law regimes characterize the approach to random closest packing.

Relaxation towards crystallization is mainly driven by grain coalescence, not classical nucleation.

Abstract

Off-equilibrium dynamics of a three-dimensional lattice model with nearest- and next nearest-neighbors exclusions is studied. At equilibrium, the model undergoes a first-order fluid-solid transition. Non-equilibrium filling, through random sequential adsorption with diffusion, creates amorphous structures and terminates at a disordered state with random closest packing density that lies in the equilibrium solid regime. The approach towards random closest packing is characterized by two distinct power-law regimes, reflecting the formation of small densely packed grains in the long time regime of the filling process. We then study the fixed-density relaxation of these amorphous structures towards the solid phase. The route to crystallization is shown to deviate from the simple grain growth proposed by classical nucleation theory. Our measurements suggest that relaxation is driven mainly by coalescence of neighboring crystallized grains which exist in the initial amorphous state.