With EDS, the elemental composition of samples can be determined (including quantitatively). All elements from atomic number 4 (beryllium) can be detected.

A central component of electron microscopic investigations is the irradiation of the samples to be examined with a fine electron beam. If the energy of the applied electron beam is high enough, the atoms of the sample are excited and emit X-rays. The atoms of a chemical element emit X-rays with an energy characteristic of that element (fingerprint).

EDS analysis detects these X-ray quanta and "sorts" them into narrow classes (channels) based on their energy. Plotting these energy channels against the number of X-ray quanta in each channel results in an EDS spectrum. Peaks in these spectra can be assigned to the characteristic energies of individual elements.

Further evaluation of these spectra makes it possible to make qualitative and even quantitative statements about the elemental composition of the sample. Our EDS software also allows for the creation of elemental maps of the sample surface (EDS mapping) or so-called line scans.

The detection limit of EDS analysis, depending on the atomic number of the element to be detected, is approximately 0.1 to 0.2 wt% (weight percent). The energy resolution is about 120 to 130 eV.

The lateral resolution of EDS analysis is limited, in analyses within an SEM, by the excited volume of the sample and is in the range of a few micrometers, depending on the sample material and excitation energy. Due to the very thin samples in a TEM, the lateral resolution here is in the range of 1 to 10 nm.

EDS analysis is installed on all our electron microscopes.