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Semiconductor Physics, Quantum Electronics & Optoelectronics. 2014. V. 17, N 3. P. 308-312.
Radiation-induced optical darkening
and oxidation effects in As2S3 glass Ivan Franko Drohobych State Pedagogical University, Abstract. The long-wave shift of fundamental optical absorption edge with decreasing the sample's transparency in the saturation region in the As2S3 bulk glass (~2 mm thick) due to radiation treatment by 60Co γ-quanta with the average energy E = 1.25 MeV and accumulated dose Φ = 2.41 MGy is reported. The red shift (radiation-induced optical darkening effect) is detected within the period of 2-3 months after γ-irradiation able to cause the well-known static radiation-induced optical effect. The detected decrease in the slope of τ(λ) curve in the fundamental optical absorption edge region after γ-irradiation, resulting in the maximum difference of optical transmittance for the unirradiated and γ- irradiated samples Δτ(hν) max at the level 33.5%, can be interpreted within the radiation- induced defect formation processes occurring in the structural network of glass. At the same time, as expected from literature, the observed decrease in the sample's transparency at the level 33% upon radiation is plausibly caused by the accompanying radiation-induced oxidation processes that are the most probably related with appearance of As2O3 (arsenolite) crystals and S phases at the surface of γ-irradiated sample, forming a white oxidized layer visible to the eye. The disadvantage of As2O3 glass to be selected as the best model object for X-ray diffraction study of γ-radiation-structural changes, especially in respect to the first sharp diffraction peak, is considered. Keywords: chalcogenide glass, optical properties, radiation modification, radiation oxidation. Manuscript received 19.02.14; revised version received 28.07.14; accepted for publication 16.09.14; published online 30.09.14.
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