The Influence of the Soft Yukawa Potential and Hard Core Interactions on Auxeticity of the Face Centered Cubic Crystal of Hard‐Core Repulsive Yukawa Particles

• Published in: physica status solidi (b) 2020-10, Vol.257 (10), p.n/a
• Main Authors: Tretiakov, Konstantin V., Wojciechowski, Krzysztof W.
• Format: Article
• Language: English
• Subjects: auxetic; elastic properties; hard spheres; negative Poisson's ratio; Yukawa potentials
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.202000194

Elastic properties and Poisson's ratio of the face centered cubic (fcc) phases of three systems of particles which interact, respectively, through: 1) hard sphere potential (HSP), 2) repulsive Yukawa potential (RYP), and 3) hard‐core repulsive Yukawa potential (HCRYP), studied by Monte Carlo (MC) simulations in the NpT ensemble, are compared in a broad range of pressures between melting and close packing. Partial auxeticity is observed in each of the considered systems and the role of the RYP and HSP, incorporated in HCRYP, is revealed. This study confirms intuitive expectations that the elastic properties of the system with particles interacting through HCRYP at high pressures are well approximated by hard spheres, whereas in the low pressures regime they are close to those obtained for the system with pure Yukawa interactions. It is also demonstrated that in the “transition region”, when the HCRYP system is neither close to RYP nor to HSP system, its Poisson's ratio in the directions [110][11¯0] exceeds the ranges given by RYP and HSP for those directions. A “transition region”, in which the elastic properties of the hard‐core repulsive Yukawa potential (HCRYP) system exceed the ranges given by the repulsive Yukawa potential (RYP) and the hard sphere potential (HSP) systems, is found. In this range of dimensionless pressure, neither RYP nor HSP dominates, and the “competition” between them strongly influences negative Poisson's ratio of the HCRYP system.