Local atomic structures of amorphous Pd₈₀Si₂₀ alloys and their configuration heredity in the rapid solidification

ABSTRACT

The local atomic structures of amorphous Pd₈₀Si₂₀ alloys and their configuration heredity in the rapid solidification are investigated by a molecular dynamics simulation with the help of cluster-type index method based on Honeycutt–Anderson bond-type index and an inversely tracking technique of atomic trajectories. Their short-range orders are found to be various Kasper clusters as well as their distorted configurations, and among which (10 2/1441 8/1551) bi-capped square Archimedean anti-prism (BSAP) clusters are dominated, e.g. Si-centred Pd₁₀Si₁ clusters. These Kasper clusters mainly exist in the form of isolated basic clusters. Few medium-range orders can be detected, especially for Si-centred Kasper clusters. Similarly to icosahedrons of Cu–Zr amorphous alloys, their sustainable configuration heredity also occurs firstly in the super-cooled liquid region, and BSAP clusters have higher onset temperature T_onset and bigger descendible fraction F than other Kasper clusters in the rapid solidification of Pd₈₀Si₂₀ alloys.

KEYWORDS:

• Pd₈₀Si₂₀ alloy
• rapid solidification
• molecular dynamics simulation
• cluster
• heredity

Acknowledgements

The computer resources at the Network Information Center of Hunan Institute of Engineering are gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is supported by the National Natural Science Foundation of China (Grant Nos. 51428101, 51661005).