Structural heterogeneity has been identified as a critical factor in determining the mechanical and thermodynamic properties of glasses. However, its influence on glass formation has not been fully understood. Here we report the nanometer-scale chemical heterogeneity of Ag in a ribbon
(at. %) metallic glass using Cs-corrected scanning transmission electron microscopy. Such heterogeneity is confirmed to occur in a
model glass when the cooling rate is tuned below
K/s, as demonstrated by a hybrid Monte Carlo molecular dynamics simulation. A structural survey of
(where
ranges from 0 to 20) model glasses cooled at
K/s reveals an inverse relationship between the fraction of icosahedral-like short-range order and the fractal dimensionality of chemical heterogeneity. Our findings demonstrate a significant role of fractal heterogeneity in promoting glass formation, a quantitative factor that has not been adequately addressed in prevailing theories of glass formation.
Link:Fractal distribution of nanoscale heterogeneity promotes the glass formation of Cu-Zr-Ag metallic glasses | Phys. Rev. B
