Study of surface degradation phenomena in cadmium red paints via bulk and surface sensitive XAS

The degradation phenomena of cadmium red (CdS1-xSex) oil paint pigments is a process that starts from the surface. We wish to study this process with a depth-selective method by using Se K-edge XAFS spectroscopy and comparing data collected simultaneously in X-ray fluorescence Yield (FY) and total electron yield (TEY) detection modes. We intend to determine the oxidation state, coordination numbers and interatomic distances of Se-compounds. These analyses will permit to define how some intrinsic properties of the pigment (crystal defects/Se content) and environmental agents influence Se speciation within cadmium red paints.