Abnormal bonding ways in Zr50Cu50 metallic glass under high pressures

The atomic structures of Zr50Cu50 metallic glasses (MGs) under high pressures from 0 GPa to 150 GPa are investigated via molecular dynamics simulations. We found that as pressure and density increase, local structural parameters such as coordination number, five-fold symmetry and quasi-nearest atom reach maxima (or minima) at 60 GPa, rather than monotonous pressure dependence. Atomic structure analyses uncover unexpected shortening of Zr-Zr bonding of Zr50Cu50 MGs under high pressures, responsible for the change of atomic packing in Zr50Cu50 MGs from dense to loose while pressure increasing. Furthermore, composition segregation is observed at high pressures, resulted from the new finding that the Zr-Zr and Cu-Cu bonding are much easier to decrease than Zr-Cu under high pressures. The results help to understand the behaviors of metallic glasses under extreme conditions. (C) 2018 Elsevier B.V. All rights reserved.