"Fractal atomic-level percolation in metallic glasses"

David Z. Chen: Crystal Y. Shi, Qi An, Qiaoshi Zeng, Wendy L. Mao,William A. Goddard III, and Julia R. Greer; Science, 09/18/15.

Additional Authors: Crystal Y. Shi, Qi An, Qiaoshi Zeng, Wendy L. Mao,William A. Goddard III, and Julia R. Greer

Abstract:

Metallic glasses are metallic alloys that exhibit exotic material properties. They may have fractal structures at the atomic level, but a physical mechanism for their organization without ordering has not been identified. We demonstrated a crossover between fractal short-range (<2 atomic diameters) and homogeneous long-range structures using in situ x-ray diffraction, tomography, and molecular dynamics simulations. A specific class of fractal, the percolation cluster, explains the structural details for several metallic-glass compositions. We postulate that atoms percolate in the liquid phase and that the percolating cluster becomes rigid at the glass transition temperature.