5.1.3 Electron microprobe analysis (SEM-EDS)

Electron microscopes (EM) usually incorporate ED and/or WD spectrometers.

The ionization cross sections for electron energies used in Electron Microscopes are higher for low energy ionization potentials. Therefore, electron microprobes are advantageous for the excitation of K-lines from low atomic number elements or the L and M lines from medium and high atomic number elements. The semiconductor detectors used for Energy Dispersive Spectrometry require of ultra-thin entrance windows, and in some cases the window can be even retracted, as to improve the detection of low emission energies.

The sensitivity of electron microprobes is limited to the analysis of major constituents, and the detection limits are typically of the order of tenths of percentages and higher.

Typical application studies include the analysis of particles and the creation of elemental / mineral composition maps.