Anomalous Diffraction Profiles of Alkali-Halide-Alkali-Cyanide Mixed Crystals

The x-ray diffraction profiles of four mixed alkali halides-alkali cyanides have been studied. At the threshold concentration where the systems change over from ferroelastic ordering to the glass state, the profiles are highly unusual. The diffracted intensity of transverse scans along the cubic axes follows $I\sim \exp (-\alpha |\xi \mathrm{}\left|\right)\mathrm{}$, where $\xi$ is the reduced wave vector, measured from the line center.