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Title: Nucleation of liquid droplets and voids in a stretched Lennard-Jones fcc crystal

The method of molecular dynamics simulation has been used to investigate the phase decay of a metastable Lennard-Jones face-centered cubic crystal at positive and negative pressures. It is shown that at high degrees of metastability, crystal decay proceeds through the spontaneous formation and growth of new-phase nuclei. It has been found that there exists a certain boundary temperature. Below this temperature, the crystal phase disintegrates as the result of formation of voids, and above, as a result of formation of liquid droplets. The boundary temperature corresponds to the temperature of cessation of a crystal–liquid phase equilibrium when the melting line comes in contact with the spinodal of the stretched liquid. The results of the simulations are interpreted in the framework of classical nucleation theory. The thermodynamics of phase transitions in solids has been examined with allowance for the elastic energy of stresses arising owing to the difference in the densities of the initial and the forming phases. As a result of the action of elastic forces, at negative pressures, the boundary of the limiting superheating (stretching) of a crystal approaches the spinodal, on which the isothermal bulk modulus of dilatation becomes equal to zero. At the boundary of the limitingmore » superheating (stretching), the shape of liquid droplets and voids is close to the spherical one.« less
Authors:
;  [1]
  1. Institute of Thermophysics, Ural Branch of the Russian Academy of Sciences, Amundsen Street 107a, 620016 Ekaterinburg (Russian Federation)
Publication Date:
OSTI Identifier:
22489647
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 97 MATHEMATICAL METHODS AND COMPUTING; CRYSTALS; DECAY; DENSITY; DROPLETS; FCC LATTICES; LIQUIDS; MOLECULAR DYNAMICS METHOD; NUCLEATION; SIMULATION; SOLIDS; STRESSES; SUPERHEATING; THERMODYNAMICS