X-ray powder microdiffraction for routine analysis of paintings

Abstract

Laboratory powder X-ray microdiffraction with a focusing monocapillary and linear multichannel detector was applied to phase identification in fragments of painting layers of art works, canvas and wall paintings, and polychromes on wood. This method is useful in materials research of painting layers with complex stratigraphy, and it is indispensable in distinguishing inorganic pigments of different natural provenance and revealing degradation products. The advantage of X-ray microdiffraction is its nondestructive nature and no need of sample pretreatment. Samples after microdiffraction can hence be used for other analyses or archived. Another advantage is the possibility to work with samples smaller than 1 mm, which is particularly important in the analysis of artworks where the sample amount or size is a serious limit of using the laboratory techniques of materials research. The X-ray equipment used is more economical and more easily accessible than other microdiffraction techniques and is, hence, suitable for routine analytical work.