Core-level and valence-band X-ray photoelectron spectroscopy was employed to study the dose-dependent radiation effects in the short-range order and the electronic structure of natural U, Th-bearing zircon near-surface layers. Single crystals from different localities (Ratanakiri, Cambodia; Mud Tank, Australia; Highlands, Sri Lanka) exhibiting wide variations in the accumulated radiation dose D≈(0 ÷ 9.2)·1018 α-decays/g was investigated. The dose values obtained by electron probe microanalysis and Raman micro-spectroscopy were used to correlate the samples with the two percolation transitions (p1, p2) in the amorphous-crystalline structure of damaged zircon. The dose-dependent variations in Eb (530.9–531.3, 101.7–102.4, 182.8- 183.3 eV) and FWHM (1.32–2.57, 1.47–1.77, 1.16 -1.55 eV) of the O1s, Si2p, and Zr3d5/2 core levels, respectively, were attributed to changes in the ensemble of non-equivalent short-range order structures. An increase in the dose resulted in the complication of the oxygen sublattice, with the following nearest environments of O atoms: (1) O (Si, [8]Zr, [8]Zr), Eb = 530.8–531.2 eV, the amount of > ~3.5 apfu (at D < p1); (2) O (Si, Si) and/or O (Si, Si, [8]Zr), Eb = 532.6 eV, the amount of ~ 0.5 ÷ 0.8 apfu (at p1 < D < p2); (3) O (Si, [7]Zr, [7]Zr), Eb = 531.6 eV, determined when the O (Si, [8]Zr, [8]Zr) amount is of ~ 1.7 apfu (at D > p2). For the first time, under an increase in the radiation dose, the oppositely directed changes in the effective charges of Si and Zr cations were detected in damaged zircon. This phenomenon was assigned to an increase in the content of the short-range order fragments characteristic of pure oxides SiO2 (namely, Si-O-Si) and ZrO2 (namely, [7]Zr) as well as to the influence of the anions O (Si, Si, [8]Zr), and the assignment was independently confirmed by the valence band analysis. The sequence of transformations in the Si-O and Zr-O sublattices was shown to be not concurrent: a partial polymerization of SiO4 tetrahedra occurs mainly at low and medium doses (D < p2) both in the crystalline and amorphous fractions, while the 7-coordinated atoms [7]Zr are mainly observed at higher doses (D > p2) in the amorphous fraction.

中文翻译：

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根据 X 射线光电子能谱研究辐射损伤锆石的短程有序和电子结构

核能级和价带X射线光电子能谱被用来研究短程有序的剂量依赖性辐射效应和天然含U、Th的锆石近地表层的电子结构。研究了来自不同地区（Ratanakiri，柬埔寨；Mud Tank，澳大利亚；Highlands，斯里兰卡）的单晶在累积辐射剂量 D≈(0 ÷ 9.2)·1018 α-衰变/g 方面表现出很大的变化。通过电子探针微量分析和拉曼显微光谱获得的剂量值用于将样品与受损锆石的非晶晶体结构中的两个渗流转变 (p1, p2) 相关联。O1s 和 Z5d、Si2d 核心水平的 Eb（530.9-531.3、101.7-102.4、182.8-183.3 eV）和 FWHM（1.32-2.57、1.47-1.77、1.16 -1.55 eV）的剂量依赖性变化分别，归因于非等效短程有序结构的集合的变化。剂量的增加导致氧亚晶格的复杂化，具有以下最近的 O 原子环境： (1) O (Si, [8]Zr, [8]Zr), Eb = 530.8–531.2 eV，数量> ~3.5 apfu（在 D < p1）；(2) O(Si, Si)和/或O(Si, Si, [8]Zr), Eb = 532.6 eV, 用量~0.5 ÷ 0.8 apfu (at p1 < D < p2); (3) O (Si, [7]Zr, [7]Zr), Eb = 531.6 eV，当 O (Si, [8]Zr, [8]Zr) 量为 ~ 1.7 apfu（在 D > p2)。在辐射剂量增加的情况下，首次在受损锆石中检测到 Si 和 Zr 阳离子有效电荷的相反方向变化。这种现象归因于纯氧化物 SiO2 特征的短程有序碎片含量的增加（即，Si-O-Si) 和 ZrO2 (即 [7]Zr) 以及阴离子 O (Si, Si, [8]Zr) 的影响，并且通过价带分析独立确认了该分配。Si-O 和 Zr-O 亚晶格中的转变序列不是同时发生的：SiO4 四面体的部分聚合主要发生在低和中等剂量 (D < p2) 的结晶和非晶部分，而 7 - 配位原子 [7] Zr 主要在更高剂量 (D > p2) 的无定形部分中观察到。