Comparison of MD Methods to Estimate the Melting Temperature of Aluminum Under High Pressure
Matheus Pianassola
Department of Materials Science and Engineering, University of Tennessee
This page shows a visualizations of the voids method applied to determine the melting temperature Tm of Al at 121 GPa. A void is created in one of the corners of the simulation box based on the fact that defects in crystals are responsible for decreasing the observed Tm.
In molecular dynamics simulations, basic thermodynamic properties such as melting temperature Tm can be obtained to either validate a model of an existing material or estimate the behavior of novel materials. In this work, Al systems are simulated under different external pressures and three methods are used to obtain the Tm: heating a perfect solid, heating a defect-containing solid (voids method), and heating a system containing solid-liquid interfaces. In all cases, the Tm is determined when a sharp decrease in density is observed. A comparison between the three methods and experimental data1 indicates that at low pressures heating a perfect lattice produce estimates close to the experimental values, while the voids method underestimates the Tm. The solid-liquid interface method is the most reliable throughout the whole pressure range studied.
Interactive Structures
Color Legend:
- blue = Al atoms
References
1. A. Hanstrom and P. Lazor, J. Alloys Compd. 305, 209, (2000).
posted: April 2020.
updated: April 2020.