New Method to Measure Structural Disorder: Application to GeO2Glass

Abstract

A new method is presented for measuring thermal or structural disorder. The additional disorder in the first Ge-O and Ge-Ge distances in amorphous Ge${\mathrm{O}}_{2}$ was measured by comparison with crystalline ($\ensuremath{\alpha}$-quartz) Ge${\mathrm{O}}_{2}$, and showed no additional disorder in the Ge-O distances but deviations in the Ge-Ge distance consistent with a \ifmmode\pm\else\textpm\fi{}6.5\ifmmode^\circ\else\textdegree\fi{} variation about a Ge-O-Ge bond angle of 130\ifmmode^\circ\else\textdegree\fi{}. These results rule out the proposed microcrystalline models.