Measurements of slow β -relaxations in metallic glasses and supercooled liquids

Dynamic mechanical measurements were performed on a series of strong and fragile metallic glass-forming liquids in isochronous and isothermal routes. Our results indicate that slow β -relaxation mode is ubiquitous in metallic glass-forming systems though it may manifest as an excess wing in strong glasses due to strong coupling with the α -relaxation. Furthermore, we find that the degree of coupling between α -relaxation and slow β -relaxation correlates with the fragility of these glass-forming liquids. The possible mechanism and the connections between α -relaxation and slow β -relaxation are discussed.