Glass transition of aluminum melt. Molecular dynamics study

• 5 metrics are used to identify the glass transition in aluminum in MD simulation.
• Splitting of the second peak in RDF follows linearly the increase of icosahedra.
• Structural and calomitric glass transition temperatures differ from each other.
• Calorimetric glass transition temperature is described by Bartenev equation.
• Structural glass transition temperature is described by Vogel–Fulcher–Tammann model.

Molecular dynamics study of transition from liquid aluminum into an amorphous state is carried out. Different criteria for the glass transition are compared with each other: splitting of the second peak of the radial distribution function, increasing of the number of atoms with icosahedron-like environment, increase of the self-diffusion activation energy, changes in the heat capacity. The discrepancy of the results obtained by different criteria is discovered. Heat capacity dependence on temperature agrees qualitatively with theoretical and experimental results. Influence of cooling rate on the glass transition temperature is studied. Although different methods give different glass transition temperatures, the dependencies on cooling rate may be interpreted in the Volkenstein and Ptitsyn's framework using either Arrhenius or Vogel–Fulcher–Tammann relaxation laws.