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Short-range ordering in metallic supercooled liquids and glasses.

Authors :
Wang, Jian Guo
Chang, Chun Tao
Song, Kai Kai
Wang, Li
Pan, Ye
Source :
Journal of Alloys & Compounds. Jan2019, Vol. 770, p386-394. 9p.
Publication Year :
2019

Abstract

Abstract The structural order in metallic supercooled liquids and glasses is a long-standing issue. Unlike the medium-range order (MRO) which involves at least hundreds of atoms, short-range order (SRO) only concerns the central atom and its neighbors, which can be described more easily. Here, we use the molecular dynamics simulation to investigate the SRO in supercooled liquids and glasses of two pure metals Ta and Ni respectively with the body-centered cubic (BCC) and the face-centered cubic (FCC) crystalline lattice and two binary alloys Cu50Zr50 and Ni50Al50 both with a B2 crystalline phase. To compare, a ternary alloy of Cu 47.5 Zr 47.5 Al 5 is also investigated. Hexagonal closed-packed (HCP) and icosahedron (ICO) clusters are found to dominate the SRO in both supercooled liquids and glasses. As expected, the glass is found more structurally ordered than the supercooled liquid. The glass transition is found to be linked to the kink of the temperature dependence of SRO. The binary system, as the relatively good glass-former, is less structurally ordered than the monatomic system as a poor glass-former, but it is more structurally ordered than the ternary one. These findings have profound implications for understanding the glass transition and designing new metallic glasses. Graphical abstract Image 1 Highlights • The HCP and ICO symmetries dominate the SRO in metallic SCLs and glasses. • The SRO is closely related with the glass transition. • The ICO clusters are not responsible for the glass forming ability. • A good glass former is structurally disordered like liquid. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
09258388
Volume :
770
Database :
Academic Search Index
Journal :
Journal of Alloys & Compounds
Publication Type :
Academic Journal
Accession number :
132487458
Full Text :
https://doi.org/10.1016/j.jallcom.2018.08.090