The evolution of structural and electronic properties during the glass transition process of Al–Ni–Nd alloy

Abstract

Ab initio molecular dynamic simulations are performed to understand the evolution of structural and electronic properties during the glass transition process of the Al–Ni–Nd alloy based on the density functional theory. The local structural evolution is evaluated by the Honeycutt–Andersen (HA) bond-type index and bond-angle distribution methods. The bond-angle distribution indicates that the close packing of three neighbour atoms and the pentagon configurations become the primary short range order (SRO) as temperature decreases and the HA bond-type result shows that the formation of the crystal structures is suppressed by the increasing pentagonal bi-pyramids ordering during the rapid solidification processes. Our result provides strong evidence for the existence of Al–Ni covalent bonds, where chemical SRO together with the polyhedral local structures play an important role during the glass transition and increase the glass forming ability of the Al–Ni–Nd alloy. We also found that the electrons with an sp character of the Al atoms are more likely to transfer to the d states of the Ni atoms during the glass transition process.