Electron spin resonance measurement of radiation-induced defects and reactions in vitreous silica irradiated with ion beams

Reaction kinetics of radiation-induced defects in vitreous silica under ion beam irradiation

“…In the case of T-2030, the density of the ODCs increases rapidly and then decreases following the growth of the ODC x s. In the case of T-4040, on the other hand, the density of the ODCs increases rather slowly with a slow growth of the ODC x s. It is interesting to point out that the formation of the cluster defects ODC x s starts above the dpa value of 10 À3 . Very similar values are obtained in radiation studies where aggregation is important, including the results of such paramagnetic centers as the E' [12,13]. The dpa value of 10 À3 corresponds to defects in every 10 Â 10 Â 10 ion cell approximately, as an indication of the interaction length/range between the ODCs (or their counterpart, interstitials).…”

“…This means that both reactions (1) and (2) are controlled in a similar way, possibly by the migration of the Os. In our recent study, the electron spin resonance measurement of irradiation defects and reactions in ion beam irradiated vitreous silica was performed in order to determine some rate constants [13]. In isothermal annealing experiments, sequential reactions of the E' centers with oxygen atoms to form the NBOHCs and PORs were observed to occur, and the activation energies were obtained to be about 0.4 eV for those reactions.…”

“…Under the present conditions of ion beam irradiation, however, an efficient defect production occurs and results in a relatively higher concentration of interstitials. The effects of various interstitial traps other than the E' centers and NBOHCs are thus considered to be negligible, similarly to the case of alumina [3] and alkali halides exposed to high dose [13].…”

Gamma irradiation and oxidative degradation of a silica-filled silicone elastomer

“…This is due to the large spin-orbit coupling constant of the oxygen atom and the small g-values reported for NBOHC and peroxy species match well to those determined for the signal we observe. [37][38][39] However, it is uncommon to see the signal of NBOHC species persist at room temperature. 37 Conversely, peroxy radicals have been observed to be relatively temperature independent when in a rigid matrix.…”

Enhanced Photoluminescence Intensity of Silicon–Germanium Nanoparticles: Silica Thin Films by Annealing in Forming Gas

“…[9][10][11] Because hydrogen gas is explosive and dangerous, many groups have tried to find an alternative annealing gas. Yang et al have investigated the PL properties of silicon NPs with thermal annealing in ambient carbon dioxide using continuous and time-resolved PL measurements.…”