Multi-analytical study of historical semiconductor pigments

This work is focused on the study of semiconductor-based pigments, which substituted traditional pigments in the second half of the 19th century. Syn- thetic semiconductor pigments may be chemically unstable due to the presence of many impurities unintentionally introduced during manufacturing. The aim of this work is to provide an insight on the application of X-ray Fluorescence (XRF) for the analysis of these painting materials, including both Cd- and Zn-based pigments. Three different approaches have been followed: the semi-quantitative analysis of samples with similar elemental composition, the complementary use of XRF and Raman spectroscopy for the analysis of elemental and molecular composition and the synchrotron-based XRF and XANES for the detection of impurities. The syn- ergetic combination of different techniques provides information useful for the defi- nition of specific markers for future analysis of paint-samples with implications for the conservation and treatment of late 19th and early 20th century paintings.