The site-selective photoluminescence spectra of -quartz samples which had been irradiated with fast neutrons, to 1018 or 1019/cm2, were studied at temperatures of between 6 and 300K under dye-laser excitation (1.9 to 2.1eV). At room temperature, an irradiation-induced photoluminescence band with a peak at 1.9eV and a decay time of 17s was found. This was similar to the photoluminescence band that was due to the non-bridging O hole centers which were characteristic of amorphous forms of this oxide. Low-temperature (less than 80K) site-selective photoluminescence spectra exhibited a number of sharp lines. Two of them (at 1.933 and 1.883eV) were identified as being zero-phonon lines that were due to 2 distinct variants of non-bridging O hole centers which were embedded in an ordered crystalline environment and underwent relatively small inhomogeneous broadening. They were superposed with a broad continuum of significantly broadened zero-phonon lines. The latter were similar to those which were observed for non-bridging O hole centers in irradiated glassy samples. Vibronic side-bands at 897/cm and 849/cm in emission spectra were attributed to the Si non-bridging O stretching mode of non-bridging O hole centers.

L.Skuja, A.Naber: Materials Science Forum, 1997, 239-241, 25-8