Caveat: measurement strategy for ultra-thin metal layers in gold leaf mosaic tesserae by Monte Carlo SEM-EDS micro- and nanoanalysis simulations

摘要

A very useful technique that can provide the local composition of a very thin material, such as the metal leaves of mosaic tesserae, is the Scanning Electron Microscopy (SEM) coupled to Energy Dispersive X-ray Spectrometry (EDS). However a careful analytical strategy must be considered when dealing with tesserae samples, because the metal leaf is extremely thin (0.2 - 1 μm), whereas the thickness of the support and the cartellina glasses are usually more than three order of magnitude thicker, and many artefacts could arise from the electron and X-Ray scattering in solids and EDS detector - sample configurations and arrangements. In order to optimize the microanalysis strategy of mosaic tesserae, in this work the effects related to the metal leaf thickness, SEM-EDS setup and detector physics were considered, providing results that could be very helpful to researchers involved in this field. Furthermore, this work provides a correct micro-nanoanalytical strategy to obtain an accurate SEM-EDS quantitative analysis also of other ultrathin layers, substrates, composites and powder materials.