Structure and dynamics of the Lennard-Jones fcc-solid focusing on melting precursors
| Autor: | Peter Mausbach, Robin Fingerhut, Jadran Vrabec |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
melting precursors solid/fluid transition General Physics and Astronomy Thermodynamics Debye-Waller factor Cubic crystal system numbers of nearest neighbors 010402 general chemistry 01 natural sciences Displacement (vector) Molecular dynamics mean-squared displacement translational order parameter 0103 physical sciences Physics::Atomic and Molecular Clusters 541 Physikalische Chemie Z method Physical and Theoretical Chemistry Range (particle radiation) 010304 chemical physics Tammann temperature Dynamics (mechanics) non-Gaussian parameter Pair distribution function vibrational density of states 0104 chemical sciences Premelting Lennard Jones fcc-solid pair distribution function Melting point ddc:541 |
| Zdroj: | The Journal of Chemical Physics. 153:104506 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/5.0015371 |
| Popis: | This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in J. Chem. Phys. 153, 104506 (2020) and may be found at https://doi.org/10.1063/5.0015371. The Lennard-Jones potential is taken as a basis to study the structure and dynamics of the face centered cubic (fcc) solid along an isochore from low temperatures up to the solid/fluid transition. The Z method is applied to estimate the melting point. Molecular dynamics simulations are used to calculate the pair distribution function, numbers of nearest neighbors, and the translational order parameter, analyzing the weakening of the fcc-symmetry due to emerging premelting effects. A range of dynamic properties, such as the mean-squared displacement, non-Gaussian parameter, Debye–Waller factor, and vibrational density of states, is considered for the analysis of the solid state. All of these parameters clearly show that bulk mobility is activated at about 2/3 of the melting temperature, known as the Tammann temperature. This indicates that vibrational motion of atoms is not maintained exclusively in the entire stable solid state and that collective atomic motion constitutes a precursor of the melting process. |
| Databáze: | OpenAIRE |
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