Correlation between glasses forming ability and density of states for the micro-alloying Al-based metallic glasses

摘要

Through study of the effect of micro-alloying on density of states at the Fermi level in the Al-based metallic glasses, we provide compelling experimental evidence that the density of electronic energy states at the Fermi level indeed is closely correlated with the glass forming ability (GFA) of metallic glasses, as predicted by the nearly free electron model. The values of the density of states at the Fermi level, N(E-F), for the Al86Ni9Y5, Al86Ni6.75Co2.25Y5 and Al86Ni6.75Co2.25Y3.25La1.75 alloys are estimated from the measurements of low-temperature specific heat (LTSH) and upper critical field (UCF). It is found that the value of N(E-F) decreases with a micro-alloying induced GFA improvement. And the decreasing of N(E-F) with Co and La alloying is due to the increasing hybridization between s and d states. Our results highlight the significance of electronic structural effects on improving GFA by micro-alloying. (C) 2020 Elsevier B.V. All rights reserved.