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

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