Elasticity of a polydisperse hard-sphere crystal

TL;DR

This paper introduces a Monte Carlo simulation method to calculate the elastic constants of polydisperse hard-sphere colloidal crystals, revealing how polydispersity affects mechanical stability and elastic properties.

Contribution

It develops a novel simulation approach for elastic constants in polydisperse crystals and identifies a critical polydispersity threshold for mechanical stability.

Findings

Elastic constants increase with polydispersity.

Pressure also increases with polydispersity.

Existence of a mechanical terminal polydispersity threshold.

Abstract

A general Monte Carlo simulation method of calculating the elastic constants of polydisperse hard-sphere colloidal crystal was developed. The elastic constants of a size polydisperse hard sphere fcc crystal is calculated. The pressure and three elastic constants(C11, C12 and C44) increase significantly with the polydispersity. It was also found from extrapolation that there is a mechanical terminal polydispersity above which a fcc crystal will be mechanically unstable.