Calorimetric study of β-relaxation in an amorphous alloy: An experimental technique for measuring the activation energy for shear transformation

• A technique for measuring the β-relaxation in amorphous alloys was proposed.
• Amorphous alloys, when preloaded at low temperature, revealed two relaxations.
• Activation energy for the β-relaxation was measured using DTA.
• Energy barrier to the β-relaxation corresponds to that to shear transformation.

When loaded at cryogenic temperature under stresses below the global yield, an amorphous alloy revealed two clearly distinguishable exothermic events during heating in calorimetric experiments. These exotherms, commonly known as the α- and β-relaxations, were attributed to the annealing out of two different local structures with different structural stability, presumably free volume and shear transformation zone (STZ). In this study, we introduced a simple and reliable experimental technique, which enables the evaluation of the activation energy corresponding to the β-relaxation, Eβ. Based on experimental evidence and comparison with earlier studies, it is presumed that Eβ is directly related to the potential energy barrier to shear transformation.