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Liquid–glass transition: A molecular dynamics study of the sodium system

1988; American Institute of Physics; Volume: 88; Issue: 3 Linguagem: Inglês

10.1063/1.454073

1520-9032

Makoto Watanabe, Kazuo Tsumuraya,

Thermodynamic properties of mixtures

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.