An intrinsic connection between the liquid-liquid transition and fragile-to-strong transition in soft magnetic Fe-based metallic glasses: Comparisons with other metallic glasses

Abstract

There are two significant abnormal transitions observed in metallic glass forming liquids (MGFLs), i.e., liquid-liquid transition (LLT) above liquidus temperature and fragile-to-strong (F-S) transition in supercooled region. In this study, we focus on the correlation between LLT and F-S transition in Fe-based soft magnetic metallic glasses (MGs) for the first time. We find that the more distinct the LLT is, the weaker is the F-S transition, and the smaller is the glass forming ability (GFA). By employing molecular dynamics simulation, we identify that this relationship is due to the inherent correlated evolution trends of crystal-like clusters between the LLT and the F-S transition regions. Moreover, we analyze a general rule regarding the LLT and F-S transition in MGs, along with their composition-dependent peculiarities. This work sheds light on the process of liquid-solid inheritance of different MGs, and deepens the understanding of the liquid dynamics of MGs and their following GFA.