REAL-SPACE STRUCTURE OF COLLOIDAL HARD-SPHERE GLASSES

The real-space structure of hard-sphere glasses quenched from colloida l liquids in thermodynamic equilibrium has been determined. Particle c oordinates were obtained by combining the optical sectioning capabilit y of confocal fluorescence microscopy with the structure of specially prepared fluorescent silica colloids. Both the average structure and t he local structure of glasses, with volume fractions ranging from 0.60 to 0.64, were in good agreement with glasses and random close packing s generated by computer simulations. No evidence of a divergent correl ation length was found. The method used to obtain the three-dimensiona l particle coordinates is directly applicable to other colloidal struc tures, such as crystals, gels, and flocs.