Surface-Resolved Mapping of Structural Disorder in Colloidal Glass-Forming Analogues

This study introduces a real-space, composition-resolved colloidal analogue to Cu–Zr metallic glasses that allows direct visualization of structural disorder and its mechanical implications. Binary polystyrene (PS) particles (183 nm and 262 nm diameters, ratio = 1:1.43) were assembled to replicate atomic-scale Cu–Zr size ratios. Two-dimensional imaging and Voronoi tessellation mapping revealed enhanced five- and seven-sided coordination and damped spatial correlations across the 21.5–66.7 at.% Zr analogue range, corresponding to the glass-forming composition window. These disorder signatures correlated with increased mechanical strength and fracture resistance, paralleling known metallic glass behavior. The approach provides a powerful optical model for linking composition-dependent disorder to glass-forming ability and mechanical stability.