Lushchik A, Kuzovkov V N, Kotomin E A, Prieditis G, Seeman V, Shablonin E, Vasil'chenko E, Popov A I
Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411, Tartu, Estonia.
Institute of Solid State Physics, University of Latvia, Kengaraga 8, Riga, 1063, Latvia.
Sci Rep. 2021 Oct 22;11(1):20909. doi: 10.1038/s41598-021-00336-0.
Due to unique optical/mechanical properties and significant resistance to harsh radiation environments, corundum (α-AlO) is considered as a promising candidate material for windows and diagnostics in forthcoming fusion reactors. However, its properties are affected by radiation-induced (predominantly, by fast neutrons) structural defects. In this paper, we analyze thermal stability and recombination kinetics of primary Frenkel defects in anion sublattice - the F-type electronic centers and complementary oxygen interstitials in fast-neutron-irradiated corundum single crystals. Combining precisely measured thermal annealing kinetics for four types of primary radiation defects (neutral and charged Frenkel pairs) and the advanced model of chemical reactions, we have demonstrated for the first time a co-existence of the two types of interstitial defects - neutral O atoms and negatively charged O ions (with attributed optical absorption bands peaked at energies of 6.5 eV and 5.6 eV, respectively). From detailed analysis of interrelated kinetics of four oxygen-related defects, we extracted their diffusion parameters (interstitials serve as mobile recombination partners) required for the future prediction of secondary defect-induced reactions and, eventually, material radiation tolerance.
由于具有独特的光学/机械性能以及对恶劣辐射环境的显著抗性，刚玉（α-Al₂O₃）被认为是未来聚变反应堆中窗口和诊断方面极具潜力的候选材料。然而，其性能会受到辐射诱导（主要是快中子）产生的结构缺陷的影响。在本文中，我们分析了快中子辐照的刚玉单晶中阴离子亚晶格中主要弗伦克尔缺陷（F型电子中心和互补氧间隙原子）的热稳定性和复合动力学。结合对四种主要辐射缺陷（中性和带电弗伦克尔对）精确测量的热退火动力学以及先进的化学反应模型，我们首次证明了两种间隙缺陷——中性O原子和带负电的O离子（分别具有峰值能量为6.5 eV和5.6 eV的归因光吸收带）共存。通过对四种与氧相关缺陷的相互关联动力学的详细分析，我们提取了它们的扩散参数（间隙原子作为可移动的复合伙伴），这些参数是未来预测二次缺陷诱导反应以及最终材料辐射耐受性所必需的。
