Effect of the entropy on the shear viscosity of metallic glasses near the glass transition

Author:

A. S. Makarov, J. B. Cui, J. C. Qiao, G. V. Afonin, N. P. Kobelev, V. A. Khonik

Keyword:

Condensed Matter, Disordered Systems and Neural Networks, Disordered Systems and Neural Networks (cond-mat.dis-nn)

journal:

date:

2023-11-19 00:00:00

Abstract

We measured the shear viscosity of 14 metallic glasses differing with their mixing entropy $\Delta S_{mix}$. It is found that the viscosity at the glass transition temperature $T_g$ significantly increases with $\Delta S_{mix}$. Using calorimetric data, we calculated the excess entropy of all glasses $\Delta S$ with respect to their maternal crystalline states as a function of temperature. It is shown that the excess entropy $\Delta S$ both at room temperature and at $T_g$ \textit{decreases} with $\Delta S_{mix}$. It is concluded that glasses with "high mixing entropy" $\Delta S_{mix}$ correspond to MGs with \textit{low} excess entropy $\Delta S$. The origin of the increased shear viscosity at $T_g$ of glasses with high $\Delta S_{mix}$ is determined by their reduced excess entropy $\Delta S$.

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