Multimodal Imaging Center (US43-UMS2016)

Ionic Microscopy (NanoSIMS) Facility

The NanoSIMS microscope is an instrument dedicated to the analysis of samples with very fine structures with heterogeneous composition.

It allows the detection of several elements or isotopes in parallel, with a lateral resolution of up to 50 nm. It offers remarkable applications in various fields, including biology (intracellular imaging, microbiology) and cosmochemistry (analysis of interplanetary dust, micrometeorites, for example).

 


NanosimsUKThe SIMS (Secondary Ion Mass Spectrometry) technique is based on the phenomenon of the emission of ions from the surface of a sample under the impact of an energetic primary ion beam.

Secondary ions from the target are characteristic of the chemical composition of sample being analyzed. Thanks to a mass spectrometer that allows the sorting of collected ions, the SIMS technique is one of the few techniques that provides in situ both elementary (including light elements such as hydrogen) and isotopic information.

When the primary beam is focused as a small spot (ionic probe), local analysis is performed. By scanning the probe, elemental and isotopic mapping of the sample surface is obtained.

One of the advantages of the SIMS technology is its high sensitivity through the use of primary ions such as O-, O2+ or Cs+ which enhance the emission of secondary ions. However, quantification of the concentration of the elements of interest is easy only in certain specific cases. On the other hand, the isotopic ratio can be measured with excellent precision.

Although the SIMS method is destructive due to the spraying of the sample surface, with this process it is possible to perform a layer-by-layer analysis, thus giving a 3D view of the sample.