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Molecular–Dynamics Based Insights into the Problem of Graphite Melting
The experimental data on graphite melting temperature remain poorly determined despite the long history of investigations. The experimental results of several works cover the wide span from 3800 to 5000 K that isan essentially larger uncertainty than the errors of individual experiments. In this work we deploy the molecular dynamics (MD) method to study the kinetics of graphite melting, concerning the aspects of defect formation and single graphene layer melting. Our MD calculations show an unexpectedly weak kinetics of the melting front propagation in graphite that is several orders slower than that in metals. We demonstrate that at sufficiently high heating rates (higher than 105 - 106 K/s) the temperatures 500-1000 K above the graphite melting temperature can be reached before the crystal decay. It allows us to explain long-standing problem of the discrepancy in the experimental data making a hypothesis that there is a strong dependence between experimentally measured graphite melting temperatures and corresponding rates of heating. © 2015 by Nova Science Publishers, Inc. All rights reserved.
