Long-term radiation-induced optical darkening effects in chalcogenide glasses

Abstract

Abstract. In this work, it is reported that the γ-irradiated (2.41 MGy accumulated dose) glasses As 2 S 3 (∼2 mm thick) and Ge 15.8 As 21 S 63.2 (∼1 mm thick), both measured ∼10 years after γ-irradiation, exhibit radiation-induced optical darkening effect (i.e., long-wave shift of fundamental optical absorption edge). In the case of As 2 S 3 glass, the observed longterm radiation-induced optical darkening effect is well comparable with that reported in literature for γ-irradiated (∼3 MGy accumulated dose) glass As 2 S 3 (1.5 mm thick), measured directly after γ-irradiation. In view of practical application, this finding demonstrates the possibilities for development of innovative chalcogenide glass based long-term dosimeter systems with stable and controlled parameters. A possible general criterion for mechanisms of long-term radiation-induced structural changes in chalcogenide glasses has been also considered.

Radiation-Induced Optical Effects in Chalcogenide Semiconductor Glasses

“…3). This approach convincingly discredit some recent speculations [35] which try to ascribe the difference in the optical transmission spectra of two ChGS samples (As2S3 and Ge15.8As21S63.2), measured a decade after γ-irradiation (=2.41 MGy), to intrinsic RIEs. Without comparison for these glasses before irradiation, these data cannot be accepted as a real signature of RIEs.…”

“…In other words, in RIEs in Ge-based ChGSs studied in direct measuring chronology, we can never distinguish (even roughly) the intrinsic "pure" radiation-induced changes like in binary As-S glasses. So the attempts of some authors [34,35] claiming the Ge-based ChGSs (like glasses of stoichiometric GeS2-As2S3 cut-section) as the ideal model object for RIEs are simply wrong and entirely misleading.…”

“…Without comparison for these glasses before irradiation, these data cannot be accepted as a real signature of RIEs. Indeed, in [35], it is ignored that difference in optical transmission spectra could be in these ChGSs just before irradiation, especially if it is accepted that these ChGSs have been affected before to a few subsequent irradiation-annealing cycles (see, for example, the results on γ-irradiation with doses =2.2 MGy [3,36,37] and =1.0 MGy [38,39]). …”