Abstract The precise study of the accumulation and subsequent thermal annealing of the defects responsible for the complex absorption band around 2.16 eV, being under discussion in the literature for a long time, has been performed in highly pure MgO single crystals exposed to 0.23-GeV 132Xe ions with a fluence of Φ = 5 × 1011 − 3.3 × 1014 ions/cm2. Three Gaussian components with the maxima at 2.16, 2.02 and 2.40 eV have been considered as a measure of so-called D1, D2 and D3 defects. Similar to the F and F+ centers, the concentration of these defects increases at high fluences without saturation marks, thus confirming their radiation-induced nature (involvement of novel Frenkel defects). The accumulation of D1 and the first stage of D-type defect annealing up to 700 K occurs similarly to single F-type centers, while the following increasing stage for D2,3 starts above 700 K; their concentration reaches the maximum at 900 K (practically plateau is seen in this temperature region for D1) and complete annealing of the D-type defects proceeds at 1100 K. Behavior of the D1 defects (accumulation rate, annealing kinetic at high temperatures) clearly differs from that for other D-type defects (especially D2). In our opinion, the D1 defects are high-order aggregates of anion vacancies (and not the anion vacancy dimers), while the involvement of additional structural defects into the D2,3 defects is suggested.

中文翻译：

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关于 MgO 晶体中 2.16-eV 吸收带的复杂性，快速 Xe 离子辐照

摘要 在暴露于 0.23-GeV 132Xe 的高纯 MgO 单晶中进行了长期在文献中讨论的 2.16 eV 附近复杂吸收带缺陷的积累和随后的热退火的精确研究。 Φ = 5 × 1011 − 3.3 × 1014 离子/cm2 的离子。最大值为 2.16、2.02 和 2.40 eV 的三个高斯分量被认为是所谓的 D1、D2 和 D3 缺陷的度量。与 F 和 F+ 中心类似，这些缺陷的浓度在没有饱和标记的高通量下增加，从而证实了它们的辐射诱导性质（涉及新的 Frenkel 缺陷）。D1 的积累和高达 700 K 的 D 型缺陷退火的第一阶段与单个 F 型中心类似，而 D2,3 的以下增加阶段开始于 700 K 以上；它们的浓度在 900 K 时达到最大值（在 D1 的这个温度区域实际上可以看到平台）并且 D 型缺陷的完全退火在 1100 K 进行。 D1 缺陷的行为（积累率，高温下的退火动力学）清楚不同于其他 D 型缺陷（尤其是 D2）。在我们看来，D1 缺陷是阴离子空位的高阶聚集体（而不是阴离子空位二聚体），而建议将额外的结构缺陷纳入 D2,3 缺陷。高温下的退火动力学）明显不同于其他 D 型缺陷（尤其是 D2）。在我们看来，D1 缺陷是阴离子空位的高阶聚集体（而不是阴离子空位二聚体），而建议将额外的结构缺陷纳入 D2,3 缺陷。高温下的退火动力学）明显不同于其他 D 型缺陷（尤其是 D2）。在我们看来，D1 缺陷是阴离子空位的高阶聚集体（而不是阴离子空位二聚体），而建议将额外的结构缺陷纳入 D2,3 缺陷。