Molecular dynamics study of thermal hysteresis during melting-crystallization of noble metals

Abstract

By constructing the thermal hysteresis of the enthalpy and density of the noble metals of gold (Au) and copper (Cu), non-equilibrium processes are investigated during the melting – crystallization phase transformations, i.e. during the solid–liquid transition. Thermal hysteresis is obtained from the atomistic modeling. The limiting temperatures of superheating of the solid phase during melting and undercooling of the liquid phase during crystallization of gold and copper are obtained. The possibility of the formation of highly superheated-undercooled metastable states of solid and liquid phases with rapid heating-cooling of the studied metals has been confirmed. The results obtained are compared with the results of alternative calculations.

Visualization Analysis of the Results of Continuum-Atomistic Modeling of a Coulomb Explosion in Metals Under the Influence of Ultrashort (fs, ps) Laser Action

“…Because of this, it is important to use a theoretical approach, the main tool of which is mathematical modeling. At present, two classes of models are most common: continuum, describing phenomena at the macrolevel [26][27][28][29][30] and atomistic, giving an idea of the phenomenon at the microlevel [31][32][33][34][35][36][37][38]. Recently, hybrid continuum-atomistic models have been developed [39,40], which combine the advantages of continuum models, which make it possible to model electronic excitation under the action of ultrashort laser radiation, and atomistic models, which allow tracking the motion of each molecule or atom, modeling detailed ablation and phase transitions after target irradiation with ultrashort laser radiation impulses.…”