SHOCK-INDUCED AMORPHIZATION OF Q-GEO2

Polycrystalline samples of the alpha-quartz phase of GeO2 (q-GeO2), re covered from peak shock compressions of 5, 6.8, and 10 GPa, have been examined by x-ray diffraction, thermoluminescence, and Raman technique s. The measurements show that q-GeO2 irreversibly amorphizes above 6.8 GPa. The estimates of the shear band temperature suggest that the mec hanism of shock-induced amorphization in q-GeO2 is a solid-solid one, in contrast to that in SiO2 quartz which has both solid-solid and fusi on-quenched components.