Second sharp diffraction peak in the structure factor of binary covalent network glasses

The second peak in the structure factor of AX₂-type glasses is found to behave in an anomalous fashion with respect to network-modifier content in a manner similar to that characteristic of the first sharp diffraction peak (FSDP). The structural origin of this newly identified second sharp diffraction peak is ascribed to interstitial-void ordering on a length scale different from that responsible for the FSDP.