On the role of Sm in solidification of Al-Sm metallic glasses

TL;DR

This study investigates how Sm influences the atomic structure during the solidification of Al-Sm metallic glasses, revealing that increased Sm promotes icosahedral clusters that enhance glass stability and formability.

Contribution

It provides new insights into the atomic-level mechanisms by which Sm enhances the glass-forming ability of Al-Sm alloys, linking structure to stability.

Findings

Increased Sm leads to more icosahedral-like clusters.

Maximum icosahedral ordering at Al90Sm10.

Minimum cohesive energy at Al93Sm7.

Abstract

During the solidification of Al-Sm metallic glasses the evolution of the supercooled liquid atomic structure has been identified with an increasing population of icosahedral-like clusters with increasing Sm concentration. These clusters exhibit slower kinetics compared to the remaining clusters in the liquid leading to enhanced amorphous phase stability and glass forming ability (GFA). Maximum icosahedral-ordering and atomic packing density have been found for the Al90Sm10 and Al85Sm15 alloys, respectively, whereas minimum cohesive energy has been found for the Al93Sm7 which is consistent with the range of compositions (from Al92Sm8 to Al84Sm16) found experimentally with high GFA.