Electron irradiation damage in quartz, SiO2

Crystallographically orientated samples of synthetic optical-grade colourless quartz with high chemical purity and low dislocation density together with synthetic gem-grade amethyst with high Fe-concentration and ca. 250 H/106 Si (“dry”) or 600 H/106 Si (“wet”) and with very high dislocation densities were irradiated using TEM. Samples of cuts perpendicular ( -cuts) and parallel ( -cuts) to the c-axis, that were as-grown or pretreated for 5 days at 820 K on air or under p(H2O)=108 Pa were prepared. Characterization methods used include AAS, FTIR, Raman-spectroscopy, X-ray-topography, REM, TEM in SAED and bright-field mode and polarized light microscopy.