Liquid-glass transition: a molecular dynamics study of the sodium system

• Published in: The Journal of chemical physics 1988-02, Vol.88 (3), p.1991-1996
• Main Authors: WATANABE, M. S, TSUMURAYA, K
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; General studies of phase transitions; Materials science; Metals, semimetals and alloys; Physics; Specific materials
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.454073

Glass formation process of the sodium system is studied by means of molecular dynamics simulation with constant volume. An equilibrium liquid with 864 atoms is cooled with the rate of 8.00×1013 K s−1 to form the glassy state. A second peak splitting of pair-distribution function (PDF) disappears at high temperatures in the glassy state region and appears clearly with decreasing temperature. The disappearance is attributed to the thermal vibration effect of atoms in the glass. The harmonic vibration model is valid in the glassy state. The Wendt–Abraham parameter, the ratio of the first minimum to the first maximum in the PDF, is 0.08 at the glass transition temperature. The value is equal to the one for the soft-core system, which is lower than the value 0.14 for the Lennard-Jones and the Gaussian-core system. The constant-volume specific heat is found to be 3 Rg in the glassy state, where Rg is the gas constant. The difference of the specific heat between the supercooled liquid and the glassy state is Rg.