Correlative Raman microscopy, SEM and EDX – fundamental consideration and project examples

The focus of this talk is to present both the fundamental and practical limitations of the emerging technique of correlative Raman-SEM-EDX microscopy and to introduce the benefits of this technique using concrete project examples.
Recent years have seen the introduction of commercially available systems that integrate fully capable Raman microscopes with scanning electron microscopes (SEM). This opens up the exciting possibilities of combining high resolution SEM and elemental analysis by energy dispersive X-ray spectroscopy (EDX) with chemical mapping by Raman microscopy for a broad audience from fundamental research to industry. However, when it comes to correlative Raman-SEM, in addition to having the equipment it is also necessary to have experience with both measurement techniques. This is due to a multitude of issues including sample preparation, beam damage/sample contamination (both electron beam and laser), correlation of the Raman mappings and the SEM-EDX data, spectral interpretation especially of the Raman spectra and the inherent limitations that are put on Raman and SEM-EDX by requirements to combine both techniques. A lot needs to be considered in correlative Raman-SEM-EDX microscopy and some general best practices guidelines are very helpful for anybody venturing into this field of research.
Our first focus is to present advice how to deal with the inherent difficulties of correlating Raman and SEM-EDX data/ measuring Raman and SEM-EDX on the same sample. Our second focus is to demonstrate the advantages of this correlative approach using examples from ongoing research projects. Therefore, we are discussing fundamental considerations and limitations that arise for all involved microscopic techniques due to the correlation, best practices guidelines during sample preparation/measurements and the benefits that correlative Raman-EDX-SEM brings especially for complex composite samples.