Abstract The oxidation of UN0.1 was studied under UHV conditions with comparison to U and UN0.68, and the nitriding effect on the electronic structure is included. A doublet characteristic of U5d spectra is evident with significant signal at 94.3 eV in the nitride samples, which is attributed to the UN component. Similar to UN0.68, a correlative oxidation behavior of UN0.1 is identified, and the multistage mechanism can be applied for the description of UN0.1 oxidation process. First, the individual reaction of U and UN with O2 leads to the formation of UO2−x and UO2 on the sample surface. Next, the generated N reacts with UN resulting in the formation of N-rich intermediate U2N3, which corresponds to the reduction in U4f peak intensity and should be in form of U2N3−xOy in presence of oxygen. When UO2 acts as a separate phase, the oxidation of UN0.1 proceeds in a different way. Based on the detail extracted from the U4f difference spectra, a complex reaction among U, UN and O2 occurs with the formation of a new U–O–N ternary compound UO2−xNy, which is further oxidized with the U4f peak shift to lower energy. The influence of the UN content in samples is revealed by the different oxidized species with characteristic electronic structure, where the oxygen vacancy concentration of UO2−xNy varies monotonously with the N content of the initial sample. The higher N content of the reactant leads to a lower vacancy concentration in UO2−xNy with a lower energy of U4f peaks. The formation of N rich UO2−x2Ny2 is speculated as an intermediate of UO2−x1Ny1 during the further oxidation. Meanwhile, both UO2−x and UO2−xNy as the oxidized species of U and UN0.1 are unstable without the O2 supply under UHV condition, but in different mechanisms.

中文翻译：

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UN0.1薄膜氧化的研究

摘要 与U 和UN0.68 相比，在UHV 条件下研究了UN0.1 的氧化，包括氮化对电子结构的影响。U5d 光谱的双峰特征很明显，氮化物样品中 94.3 eV 的显着信号，这归因于 UN 成分。与UN0.68类似，确定了UN0.1的相关氧化行为，可以应用多阶段机理描述UN0.1氧化过程。首先，U 和 UN 与 O2 的单独反应导致在样品表面形成 UO2-x 和 UO2。接下来，生成的 N 与 UN 反应导致形成富含 N 的中间体 U2N3，这对应于 U4f 峰强度的降低，并且在氧气存在下应以 U2N3-xOy 的形式存在。当 UO2 作为一个单独的相时，UN0 被氧化。1 以不同的方式进行。根据从 U4f 差异光谱中提取的细节，U、UN 和 O2 之间发生了复杂的反应，形成了新的 U-O-N 三元化合物 UO2-xNy，随着 U4f 峰移至较低能量而进一步氧化. 样品中UN含量的影响通过具有特征电子结构的不同氧化物种来揭示，其中UO2-xNy的氧空位浓度随初始样品的N含量单调变化。反应物中较高的 N 含量导致 UO2-xNy 中的空位浓度较低，U4f 峰的能量较低。在进一步氧化过程中，富含 N 的 UO2−x2Ny2 的形成被推测为 UO2−x1Ny1 的中间体。同时，UO2-x 和 UO2-xNy 作为 U 和 UN0 的氧化物质。