Comparison of different correlative AFM-SEM workflows on calcite moonmilk

Abstract

In recent years, high resolution microscopy techniques are evolving toward a fast combination of different microscopies and spectroscopies, generally labelled under the title of correlative microscopy, each capable to provide unique information and a more comprehensive characterization of the sample under analysis. Among them stands out the Correlative Probe to Electron Microscopy (CPEM), where Scanning Electron Microscopy and Scanning Probe Microscopy are combined. This kind of technique is relatively new, and its range of capabilities is still not fully explored. In this paper, a demonstration of different CPEM workflows to characterize the moonmilk, a particular type of nanostructured calcium carbonate, extracted from ancient tombs of the Etruscan Necropolis of Tarquinia, is provided. Besides, the advantages of an innovative AFM-in-SEM setup, even respect to the standard standalone AFM measurement, are presented, showing how the analysis of the moonmilk nano-fibers, a rather challenging sample to be analysed with probe microscopies, is simplified and with less risk of artefacts or contamination of the AFM probe.