Spectroscopic studies of defects in gamma- and neutron-irradiated magnesium aluminates spinel ceramics

• Main Authors: Kazarinov, Yu., Kvatchadze, V., Gritsyna, V., Abramishvili, M., Akhvlediani, Z., Galustashvili, M., Dekanozishvili, G., Kalabegishvili, T., Tavkhelidze, V.
• Format: Article
• Language: English
• Published: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2017
• Series: Вопросы атомной науки и техники
• Subjects: Физика радиационных повреждений и явлений в твердых телах
• Online Access: http://dspace.nbuv.gov.ua/handle/123456789/136165

The spectroscopic investigations of defects in optical spinel ceramics irradiated with gamma-rays from ⁶⁰Co source and mixed neutron-gamma field in WWR reactor to neutron fluences of 1·10¹³ and 5·10¹³ n/cm² were provided. The obtained data on the dose dependence of intensity of absorption bands in the visible range allow to identify the origin of optical centers formed under irradiation. Absorption in IR range indicates on the presence in ceramics carbon-related complexes that become active after irradiation. The registered EPR signal of g = (2.0174±0.0005) and width of (46.1±1.5) G which corresponds to HO₂⁻ or O₃⁻ radicals. The dependences of the investigated centers on annealing temperature of the irradiated spinel ceramics show unusual increase in intensity of absorption and steady-state radio-luminescence in the temperature range of 200…400 °C. The role of complexes of defects including anti-site defects in formation and healing of defects in different temperature ranges are analyzed taking into account different mobility of cations and anions and specific mechanism of radio-luminescence.