Hidden and universal relaxation mode in metallic glasses of simple atomic structure

Relaxation inherently relates to the nonequilibrium nature of glassy solids and has profound influences on their properties. Exploring diverse relaxation modes of glasses is central to understanding their complicated dynamic behaviors and the nature of glass transition. Here, we report a hidden and universal relaxation mode (termed alpha' relaxation)-which emerges between alpha relaxation and relaxation in metallic glasses with relatively simple atomic structure-by systematically investigating their dynamic modulus spectrum. We find that the excitation of the alpha' relaxation mode is controlled by the energy state and the local potential energy topology around the state. A notable alpha' relaxation can only appear at an intermediate range of energy states, and it can be manipulated by annealing or rejuvenating. The activation energy and the nonmonotonic behavior of alpha' relaxation reveal that it intrinsically connects alpha relaxation and relaxation. Furthermore, we also show that the excitation of the alpha' relaxation mode, rather than the level of the energy state, can notably improve the homogeneous tensile deformability of metallic glasses.

Automated summary

In this study, a hidden and universal relaxation mode (termed alpha' relaxation) was discovered in metallic glasses, which appears between alpha relaxation and relaxation. The excitation of the alpha' relaxation mode is found to be controlled by the energy state and the local potential energy topology. It was also observed that the activation energy and nonmonotonic behavior of alpha' relaxation reveal its intrinsic connection with alpha relaxation and relaxation. Furthermore, it was shown that the excitation of the alpha' relaxation mode can notably improve the homogeneous tensile deformability of metallic glasses.