The correlation between β relaxation and shear transformation zone in LaNiAl bulk metallic glasses: The effect of cryogenic thermal cycling treatment

Despite the general acceptance that beta relaxation and shear transformation zone (STZ) may share similar microstructure origin and possess identical activation energies, i.e., E-beta = W-STZ, in this study, we experimentally demonstrate opposite changing trends of the two energies could be derived in La60Ni25Al15 metallic glass before and after cryogenic thermal cycling treatment with distinct temperature intervals. Specifically, the experimental results indicate larger STZ requires higher W-STZ, while lower E-beta is needed to activate the atoms involved in string-like motions that corresponding to easier beta relaxation. The results of this article will deepen our understanding of the correlation between relaxation and deformation carriers of the La-based metallic glasses. (C) 2021 Published by Elsevier B.V.

Automated summary

This study found opposite changing trends of activation energies for beta relaxation and STZ in La60Ni25Al15 metallic glass before and after cryogenic thermal cycling treatment. Specifically, larger STZ requires higher W-STZ, while lower E-beta is needed to activate atoms involved in string-like motions. These results will deepen our understanding of the correlation between relaxation and deformation carriers in La-based metallic glasses.