Structural evolution in Au- and Pd-based metallic glass forming liquids and the case for improved molecular dynamics force fields

F Z Chen; K Ruhland; C Umland; S M Bertrand; A J Vogt; K F Kelton; N A Mauro

doi:10.1063/5.0123907

Structural evolution in Au- and Pd-based metallic glass forming liquids and the case for improved molecular dynamics force fields

J Chem Phys. 2022 Nov 21;157(19):194501. doi: 10.1063/5.0123907.

Authors

F Z Chen¹, K Ruhland², C Umland², S M Bertrand², A J Vogt³, K F Kelton¹, N A Mauro²

Affiliations

¹ Institute of Materials Science and Engineering, Washington University, St. Louis, Missouri 63130, USA.
² Department of Physics, St. Norbert College, De Pere, Wisconsin 54115, USA.
³ Department of Physics, Washington University, St. Louis, Missouri 63130, USA.

PMID: 36414450
DOI: 10.1063/5.0123907

Abstract

The results of a combined experimental and computational investigation of the structural evolution of Au₈₁Si₁₉, Pd₈₂Si₁₈, and Pd₇₇Cu₆Si₁₇ metallic glass forming liquids are presented. Electrostatically levitated metallic liquids are prepared, and synchrotron x-ray scattering studies are combined with embedded atom method molecular dynamics simulations to probe the distribution of relevant structural units. Metal-metalloid based metallic glass forming systems are an extremely important class of materials with varied glass forming ability and mechanical processibility. High quality experimental x-ray scattering data are in poor agreement with the data from the molecular dynamics simulations, demonstrating the need for improved interatomic potentials. The first peak in the x-ray static structure factor in Pd₇₇Cu₆Si₁₇ displays evidence for a Curie-Weiss type behavior but also a peak in the effective Curie temperature. A proposed order parameter distinguishing glass forming ability, 1/ST,q₁-1, shows a peak in the effective Curie temperature near a crossover temperature established by the behavior of the viscosity, T_A.