Correlation of viscosity with atomic packing in Cu50Zr50 melt

The viscosities of Cu50Zr50 melt from 1250 K to 1435 K were measured in a containerless electromagnetic levitator under microgravity. The viscosity in the investigated temperature range can be expressed by an Arrhenius temperature dependence η(T) = η0 exp(EA/kBT), with η0 = (0.08 ± 0.02) mPa·s and EA = (0.58 ± 0.03) eV. We find a correlation between the fraction of closer neighboring atoms, f, and viscosity, which is described by η = expnfm, where n = 1.746/Δpec-4.478, m = −0.374/Δpec + 0.440, and Δpec is the excess potential energy, indicating that the temperature dependent viscosity during cooling is controlled by the fraction of closer neighboring atoms. •Viscosity of Cu50Zr50 liquid follows Arrhenius law.•Excessive potential energy of atoms descripts the local stability.•Correlation between viscosity and structural is expressed by VF function.