Pressure-induced atomic packing change in Pd37Ni37S26 metallic glass

Pressure-dependent atomic packing structure changes of newly designed sulfur-bearing metallic glass (MG) of Pd37Ni37S26 have been studied by in situ high energy X-ray diffraction and resistivity experiments, and ab initio molecular dynamics simulations from ambient pressure up to 40.9 GPa. Local structural transformation from a low-density amorphous state into high-density one at about 12.8 similar to 15.4 GPa has been revealed, which originates from the noticeable kinks during the electron back-donations from S atoms to more localized Ni 3d orbital at about 13 similar to 15 GPa and is confirmed by the pressure-dependent resistivity measurements. The origin for the transition is uncovered, i.e., Pd- and Ni-centered clusters first transfer from icosahedral-like structures into higher-coordinated ones, which dominates the initial densification of Pd37Ni37S26 MG during the compression below 13 GPa. In the pressure range above 15 GPa, the low-coordinated S-centered clusters transform into the tri-capped trigonal prism-like structures during the compression of Pd37Ni37S26 MG up to 40.9 GPa. All results obtained here provide insight into the local structural evolution of the sulfur-bearing MGs with pressure. (C) 2021 Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Automated summary

The pressure-dependent atomic packing structure changes of newly designed sulfur-bearing metallic glass Pd37Ni37S26 have been investigated in this study, revealing local structural transformation and cluster transitions under different pressures. The results provide insights into the local structural evolution of sulfur-bearing metallic glasses under pressure.