Ghirardello Marta, Gonzalez Victor, Monico Letizia, Nevin Austin, MacLennan Douglas, Patterson Catherine Schmidt, Burghammer Manfred, Réfrégiers Matthieu, Comelli Daniela, Cotte Marine
Physics Department, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
Université Paris-Saclay, ENS Paris-Saclay, CNRS, PPSM, 91190 Gif-sur-Yvette, France.
Microsc Microanal. 2022 May 30:1-10. doi: 10.1017/S1431927622000873.
The cultural heritage community is increasingly exploring synchrotron radiation (SR) based techniques for the study of art and archaeological objects. When considering heterogeneous and complex micro-samples, such as those from paintings, the combination of different SR X-ray techniques is often exploited to overcome the intrinsic limitations and sensitivity of the single technique. Less frequently, SR X-ray analyses are combined with SR micro-photoluminescence or micro-Fourier Transform Infrared spectroscopy, which provide complementary information on the molecular composition, offering a unique integrated analysis approach. Although the spatial correlation between the maps obtained with different techniques is not straightforward due to the different volumes probed by each method, the combination of the information provides a greater understanding and insight into the paint chemistry. In this work, we discuss the advantages and disadvantages of the combination of X-ray techniques and SR-based photoluminescence through the study of two paint micro-samples taken from Pablo Picasso's Femme (1907). The painting contains two cadmium yellow paints (based on CdS): one relatively intact and one visibly degraded. SR micro-analyses demonstrated that the two Cd-yellow paints differ in terms of structure, chemical composition, and photoluminescence properties. In particular, on the basis of the combination of different SR measurements, we hypothesize that the degraded yellow is based on nanocrystalline CdS with high presence of Cd(OH)Cl. These two characteristics have enhanced the reactivity of the paint and strongly influenced its stability.
文化遗产领域越来越多地探索基于同步辐射（SR）的技术来研究艺术品和考古文物。在考虑异质且复杂的微样本时，例如来自绘画的样本，常常会利用不同的SR X射线技术相结合的方式，来克服单一技术固有的局限性和敏感性。较少情况下，SR X射线分析会与SR微光致发光或微傅里叶变换红外光谱相结合，这些技术能提供关于分子组成的补充信息，从而提供一种独特的综合分析方法。尽管由于每种方法探测的体积不同，用不同技术获得的图谱之间的空间相关性并不直接，但信息的结合能让人对绘画颜料的化学性质有更深入的理解和洞察。在这项工作中，我们通过研究取自巴勃罗·毕加索的《女人》（1907年）的两个绘画微样本，讨论了X射线技术与基于SR的光致发光相结合的优缺点。这幅画包含两种镉黄颜料（基于硫化镉）：一种相对完好，另一种明显降解。SR微分析表明，这两种镉黄颜料在结构、化学成分和光致发光特性方面存在差异。特别是，基于不同SR测量结果的结合，我们推测降解的黄色颜料是基于含有大量氯氧化镉的纳米晶硫化镉。这两个特征增强了颜料的反应活性，并强烈影响了其稳定性。
