Luminescence of SiO 2 quartz induced by swift heavy ion irradiations

Abstract

We have studied the luminescence of natural SiO 2 quartz induced by irradations with heavy ions in the MeV amu −1 range. The spectra obtained with sample temperatures of ∼ 85 K have the same features and line shapes, irrespective of the fluence ( φt) and electronic stopping power ( S e) of the different ions (from 12C to 127I). The spectra are least-squares fitted with three Gaussian functions centered at 440 nm (2.8 eV), 500 nm (2.5 eV), and 740 nm (1.65 eV). When increasing φt, the intensities ( I) of all three bands decrease and the decrease is fitted by, approximately, an exponential law, i.e., I = I o exp( − σφt), with approximately the same decay cross-section (σ), σ is found to increase by one order of magnitude when increasing S e above the amorphous track formation threshold at 2.5 keV nm −1. Above this threshold, σ is also larger than the track core cross-section by one order of magnitude and does not vary versus S e. These data are interpreted by the interactions of the self-trapped excitons (STEs) with the ion-induced defects increasing the non-radiative recombinations of the STEs.