The structural and dynamic heterogeneities of Ni-P nanoglass characterized by stress-relaxation

Abstract

The method of stress-relaxation is applied to study the structural and dynamic heterogeneities of Ni-P nanoglass (NG) prepared by pulse electro-deposition. We provide direct evidence that the Ni-P NG has more flow units with better plasticity than conventional Ni-P metallic glass (MG) prepared by rapid quenching. Moreover, an anomalous peak is observed in the activation energy spectra of NG at 435 K, which may relate to a hidden polyamorphous phase transition in Ni-P NG. Our study provides insights on the understanding of the discrepancy in structural heterogeneity and dynamic and thermodynamic properties between the NG and MG. • Ni-P NG has the stronger structural heterogeneity and more flow units than MG by stress-relaxation. • An anomalous thermal expansion was found in NG at 435 K. • A phase transition happend in NG at 435 K which is related to polyamorphous phase transition.