Na-irradiated alpha-quartz: chemical epitaxy and luminescence

"Doping of alpha-quartz by ion implantation leads to amorphization even at low fluences, but subsequent annealing in air or oxygen can restore the crystalline order (chemical epitaxy). Here we report on measurements of RBS channeling and cathodoluminescence (CL) spectra during chemical epitaxy of alpha-quartz irradiated with 50-keV Na-ions and annealed in O-18(2)-gas. In particular, the variation of the damage profile and CL spectra (the latter taken at 10 K and 300 K) as functions of the ion fluence will be discussed. The CL spectra at 10 K are dominated by a 2.90-eV band and differ greatly from the ones taken at 300 K; the intensity of this band increases strongly with the Na ion fluence. Some conclusions concerning the underlying photoactive defect structures will be drawn."