Elastic properties and atomic bonding character in metallic glasses

The elastic properties of glasses from different metallic systems were studied in the light of the atomic packing density and bonding character. We found that the electronegativity mismatch (Delta e(-)) between the host-and the major solute-elements provides a plausible explanation to the large variation observed for Poisson's ratio (v) among metallic glasses (MGs) (from 0.28 for Fe-based to 0.43 for Pd-based MGs), notwithstanding a similar atomic packing efficiency (C-g). Besides, it is found that ductile MGs correspond to Delta e(-) smaller than 0.5 and to a relatively steep atomic potential well. Ductility is, thus, favored in MGs exhibiting a weak bond directionality on average and opposing a strong resistance to volume change. (C) 2015 AIP Publishing LLC.