Amorphous alloys: Reflections from the glass maze

The internal structure of amorphous alloys was initially described as random packing of hard spheres. The internal structure of amorphous alloys was initially described as random packing of hard spheres. Even high-resolution transmission electron microscope (TEM) images, which otherwise are able to resolve lattice fringes in crystals, display only a maze-like pattern with no discernable structure. The subnanometer beam size used by Hirata and colleagues, in contrast, is sufficiently small to address individual polyhedra, and the researchers are consequently able to observe distinct diffraction spots in symmetric patterns that resemble those for single crystals to some extent. The dependence of local structure on alloy composition may now be confirmed experimentally.