Signature of Al11Sm3 fragments in undercooled Al90Sm10 liquid from ab initio molecular dynamics simulations

TitleSignature of Al11Sm3 fragments in undercooled Al90Sm10 liquid from ab initio molecular dynamics simulations
Publication TypeJournal Article
Year of Publication2011
AuthorsFang XW, Wang CZ, Yao YX, Ding ZJ, Ho KM
Journal TitleJournal of Physics-Condensed Matter
Volume23
Pages235104
Date Published06
Type of ArticleArticle
ISBN Number0953-8984
Accession NumberISI:000290957300030
Keywordsalloy, clusters, crystallization behavior, metallic glasses, RANGE ORDER, total-energy calculations, wave basis-set
Abstract

An ab initio molecular dynamics (MD) simulation is performed to investigate the structural evolution in Al90Sm10 liquid from 1500 to 900 K. Development of Al11Sm3 local order upon rapid cooling is suggested by the Honeycutt-Anderson (HA) index analysis and the appearance of a predominant Sm-Sm-Sm bond angle around 90 degrees when the liquid approaches the melting point (similar to 920 K). Direct structural evidence of Al11Sm3 fragments at 900 K is obtained using an atomic cluster alignment method developed recently. Meanwhile, development of strong icosahedral short range order (ISRO) and a non-negligible amount of fcc-type clusters around Al in the system are also observed. These results suggest that fcc Al and Al11Sm3 crystalline phases would compete strongly with the formation of an amorphous phase that exhibits ISRO in the diffusionless solidification limit upon rapid quenching.

URL<Go to ISI>://000290957300030
DOI10.1088/0953-8984/23/23/235104
Alternate JournalJ. Phys.-Condes. Matter