The study of radiation degradation of optical properties of non-stoichiometric Lu3.01−xYxAl4.99O12 crystals doped with Ce3+, Cr3+, and Sc3+ ions under the action of gamma radiation

Abstract

The spectra of pulsed cathodoluminescence (PCL) and optical transmission (OT) of crystals grown from Lu_3.01−xY_xAl_4.99O₁₂ melts doped with Cr³⁺, Ce³⁺, and Sc³⁺ ions before and after irradiation with gamma radiation of a ⁶⁰Co radioactive source are studied. The gamma radiation dose absorbed by samples was 45 Mrad. The maximum gamma-radiation-induced absorbance in the range of 525–700 nm was 0.48 cm⁻¹. Changes in the PCL and OT spectra of all samples after irradiation were detected. It was found that the relative intensity of Cr³⁺ bands increased after irradiation in relation to the Ce³⁺ band intensity by a factor of 1.6–8; the OT spectra of all samples after irradiation lost specific features and became identical. The results obtained are qualitatively explained. According to the explanation, the induced absorption is controlled first of all by optically active Frenkel defects formed after irradiation, which include an oxygen vacancy and an interstitial oxygen ion.