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 beta-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 alpha-relaxation. Furthermore, we find that the degree of coupling between alpha-relaxation and slow beta-relaxation correlates with the fragility of these glass-forming liquids. The possible mechanism and the connections between alpha-relaxation and slow beta-relaxation are discussed.