High-pressure structural study ofGeI4s

We have measured x-ray diffraction from a disordered phase of ${\mathrm{GeI}}_4$ , formed by reversible pressure-induced amorphization above 33 GPa. These are the first quantitative, in situ diffraction measurements on a pressure-amorphized material, and they show that the x-ray scattering from disordered ${\mathrm{GeI}}_4$ significantly exceeds that of conventional amorphous materials. For this phase, the peak positions in the structure factor [S(Q)] resemble low-pressure Bragg diffraction and the interatomic correlations [G(r)] are similar to the low-pressure crystalline structure over distances of 16 Å.