Multilayered samples reconstructed by measuring Kα/K β or Lα/Lβ X-ray intensity ratios by EDXRF

In this paper a general method based on energy-dispersive X-ray fluorescence (EDXRF) analysis has been
tested to assess its possible use as a tool to reconstruct the structure and determine the thickness of two
and/or multi-layered materials. The method utilizes the X-ray intensity ratios of Ka/Kb or La/Lb peaks (or
the ratio of these peaks) for selected elements present in multi-layered objects of various materials (Au
alloys, gilded Cu, gilded Ag, gilded Pb, Ag–Au Tumbaga, stone surfaces with protective treatments, Zn or
Nickel plating on metals). Results show that, in the case of multi-layered samples, a correct calculation of
the peak ratio (Ka /Kb and/or La/Lb) of relevant elements from energy-dispersive X-ray fluorescence spectra,
can provide important information in assessing the exact location of each layer and for calculating its
thickness. The methodological approach shown may have important applications not only in materials
science but also when dealing with the conservation and restoration of multi-layered cultural heritage
objects where the use of a Non-Destructive techniques to determine slight chemical and thickness
variations in the layered structure is often of paramount importance to achieve the best results.