Evidence for Glass Behavior in Amorphous Carbon

Round 1

Reviewer 1 Report

The authors used computational methods to investigate the behavior of carbon structures in the quenching process from high temperatures. The reported results, comparing different potentials, evidence the presence of a slope change in the Arrhenius plots for the diffusion coefficient that is interpreted as mark of a glass transition. The reported analysis enables to predict the glass transition temperature and the melting temperature. The comparison among the potentials enables to determine a range of temperatures and the critic comparison with literature data. In my opinion the manuscript is clear and well organized and could be published in its present form.

Reviewer 2 Report

The study was devoted to the theoretical consideration of the phase transition in the carbon. The authors have come to a conclusion, that that amorphous carbon has a well-defined glass-transition temperature, and it was a main output of the article. This result was very well supported by numerical simulation. However, the proposed temperature of melting was very high, and the experimental confirmation of this output is hard to achieve.

I cannot imagine where we can apply such knowledge, so the applicative impact of the article is limited. However, it is a good piece of work as far as basic knowledge is considered. The article presents a very high scientific level. All theoretical consideration has a solid background and is very well described. I cannot find any serious flaws in the article. I’m pleased to recommend the article to print in a current form.