Elastic properties of three-dimensional Yukawa or dust crystals from molecular dynamics simulations

TL;DR

This study uses molecular dynamics simulations to calculate the elastic properties of three-dimensional Yukawa or dust crystals, revealing temperature-dependent behaviors and phase transition indicators.

Contribution

It provides the first finite-temperature calculations of bulk and shear moduli for Yukawa crystals, enhancing understanding of their elastic behavior near phase transitions.

Findings

Finite-temperature bulk modulus exceeds 0 K values.

Shear modulus decreases near the solid-liquid boundary.

Poisson's ratio sharply changes at phase transition.

Abstract

This paper presents the calculation of elastic properties of three-dimensional Yukawa or dust crystals using molecular dynamics (MD) simulations. The elastic properties are computed by deforming (compressing/expanding) the dust crystals along different directions. The stress and strain of the deformed crystal are used to calculate elastic properties. The bulk modulus, shear modulus, and Poisson's ratio are determined as a function of shielding parameter $\kappa$ and strong coupling parameter $\Gamma$. The bulk and shear modulus values at 0 K temperature are consistent with the previous literature results, while the finite-temperature results are new. The finite-temperature bulk modulus of Yukawa crystals is found to be higher than that of 0 K crystals. The shear modulus of the Yukawa solids decreases nonlinearly near the solid-liquid boundary in the premelting region. The Poisson's ratio of Yukawa crystals changes sharply at the solid-liquid boundary, emphasizing its potential for identifying phase transitions and assessing incompressibility in Yukawa systems. The bulk and shear moduli calculated in this paper are useful for determining accurate values of sound and shear velocity in Yukawa systems across a wide range of the ($\kappa$, $\Gamma$) parameter space.