The preservation of bronze and copper heritage objects is challenging. Exposure to water or pollution in outdoor conditions leads to corrosion phenomena, which can highly degrade the objects or structures. We aim to develop an alternative nontoxic corrosion inhibiting treatment, based on the use of a carboxylate (HC₁₀) treatment. Electron spectroscopies (X‐ray photoelectron spectroscopy and scanning Auger microscopy) are used to determine, from micrometric to nanometric scale, the composition and chemical environments (oxidation degrees) of the copper compounds commonly found in the corrosion product layer. In the present study, we focus on the evaluation of X‐ray beam irradiation damage when performing surface analysis on cuprite, brochantite, and Cu decanoate reference samples. The reduction phenomenon has already been reported, especially for Cu(II) compounds, but not clearly explained. Different behavior has been observed depending on the X‐ray source used, and the nature and hydration level of the compounds. The photoreduction issue is critical, as it guarantees the reliability of the chemical information obtained and sheds light on the best analysis pathway to adopt when multitechnique analyses are implemented. An analytical procedure is employed to track the reduction of Cu(II) reference samples during XPS analysis evidencing practically instantaneous modifications of the spectra and thus, the instability of these phases except for the dehydrated cuprite sample.

中文翻译：

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铜化合物的X射线光电子能谱表征，用于开发专用于遗产铜物体保存的有机保护处理

青铜和铜质遗产的保存是一项挑战。在室外条件下暴露于水或污染会导致腐蚀现象，这会严重破坏物体或结构。我们旨在基于羧酸盐（HC ₁₀）治疗。电子光谱学（X射线光电子能谱和扫描俄歇显微镜）可用于确定腐蚀产物层中常见的铜化合物的组成和化学环境（氧化度），从微米级到纳米级。在本研究中，我们专注于在对铜矿，青铜矿和癸酸铜参考样品进行表面分析时评估X射线束的照射损伤。已经报道了还原现象，特别是对于Cu（II）化合物，但没有明确解释。根据所使用的X射线源以及化合物的性质和水合水平，观察到了不同的行为。光电还原问题很关键，因为它可以确保获得的化学信息的可靠性，并为实施多技术分析提供了最佳的分析途径。在XPS分析过程中，采用分析程序来跟踪Cu（II）参考样品的还原，从而证明光谱实际上是瞬时修饰的，因此，除了脱水的铜矿样品外，这些相的不稳定性。