Realistic three-dimensional atomistic structures of ${\text{Zr}}_x{\text{Cu}}_{100-x}$ $\left(x=35,50\right)$ bulk metallic glasses are constructed using a combination of x-ray diffraction experiment and computational modeling. A cluster correlation method is developed to analyze the medium-range order in amorphous systems. We show that the glass systems consist of a stringlike backbone network formed by icosahedral clusters and a liquidlike structure filling in the remaining space. These findings are consistent with those obtained from our independent classical molecular-dynamics studies with embedded-atom method potential for ZrCu system. Such a heterogeneous structure provides a fundamental structural perspective of dynamical heterogeneity and glass formation.

• Received 1 December 2008

DOI:https://doi.org/10.1103/PhysRevB.80.184201