Experimental determination of the temperature-dependent Van Hove function in a Zr80Pt20 liquid

R Ashcraft; Z Wang; D L Abernathy; D G Quirinale; T Egami; K F Kelton

doi:10.1063/1.5144256

Experimental determination of the temperature-dependent Van Hove function in a Zr₈₀Pt₂₀ liquid

J Chem Phys. 2020 Feb 21;152(7):074506. doi: 10.1063/1.5144256.

Authors

R Ashcraft¹, Z Wang², D L Abernathy³, D G Quirinale⁴, T Egami², K F Kelton¹

Affiliations

¹ Department of Physics, Washington University, St. Louis, Missouri 63130, USA.
² Department of Materials Science and Engineering, Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
³ Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
⁴ Neutron Technologies Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.

PMID: 32087649
DOI: 10.1063/1.5144256

Abstract

Even though the viscosity is one of the most fundamental properties of liquids, the connection with the atomic structure of the liquid has proven elusive. By combining inelastic neutron scattering with the electrostatic levitation technique, the time-dependent pair-distribution function (i.e., the Van Hove function) has been determined for liquid Zr₈₀Pt₂₀. We show that the decay time of the first peak of the Van Hove function is directly related to the Maxwell relaxation time of the liquid, which is proportional to the shear viscosity. This result demonstrates that the local dynamics for increasing or decreasing the coordination number of local clusters by one determines the viscosity at high temperature, supporting earlier predictions from molecular dynamics simulations.