Exploration of the atomic-level structures of the icosahedral clusters in Cu-Zr-Al ternary metallic glasses via first-principles theory

The atomic-level structures of the icosahedral clusters in Cu-Zr-Al ternary metallic glasses were studied via the first-principles theory. The rules of icosahedra stability were determined. Icosahedra with a better chemical order or with a better symmetry exhibited a better stability. The strong connectivity between Al atom and Cu and Zr atoms was observed as demonstrated by the obvious degree of 'bond shortening'. The Al atom contributed more to the structural stability when used as the central atom than the other atoms. Therefore, the addition of even a small amount of Al atom to the Cu-Zr binary system remarkably improved the stability of the icosahedron structures. The continued addition of Al atoms had a lower contribution to the improvement to the glass-forming ability of the Cu-Zr-Al alloys.

Automated summary

The atomic-level structures of icosahedral clusters in Cu-Zr-Al ternary metallic glasses were studied using first-principles theory. The stability rules for icosahedra were determined, showing that better chemical order and symmetry result in better stability. Strong connectivity between Al atoms and Cu-Zr atoms was observed, with Al atoms playing a greater role in structural stability when used as the central atom. Therefore, adding even a small amount of Al atom can significantly improve the stability of icosahedral structures in the Cu-Zr binary system, but further additions have a lower contribution to the glass-forming ability of Cu-Zr-Al alloys.