Liu, Y.; Wang, J.; Qin, J.; Schumacher, G.: Influence of Ag substitution on the local structure of Al86Ni(8-x)Y6Agx (X=0,1,2) melts and glasses. Physics and Chemistry of Liquids 54 (2016), p. 98-109
10.1080/00319104.2015.1084880
Abstract:
The local structure of Al86Ni(8-x)Y6Agx (X=0,1,2) molten and glassy alloy was investigated by ab-initio molecular dynamics simulation. It turned out that the Al86Ni(8-x)Y6Agx alloy can be considered as a combination of Ni-centred Al clusters and Y-centred Al clusters with Ag as “glue atoms”. First and second Ag-Ag coordination were scarcely found in Al86Ni7Y6Ag1, but a medium-range order between 7.5-9 Å was observed. The better glass forming ability and thermal stability of the alloy compared to Al86Ni8Y6 can be attributed to the medium-range order of the Ag-Ag correlation. Second Ag-Ag coordination occurs in Al86Ni6Y6Ag2 and causes a decrease in glass forming ability. The interatomic distances between all constituting elements increase during cooling. This increase is ascribed to a change in distribution of clusters around Al atoms towards clusters with higher coordination number around Al.