Factors Affecting Quantitative EDS Analysis in the TEM
It is often assumed that EDS analysis on (S)TEM is straightforward.
However, many factors may affect both quantitative and qualitative results.
These include microscope alignment, sample holders, apertures as well as sample
thickness, density and homogeneity. Careful sample preparation is essential for
accurate quantitative results and usually a number of measurements are necessary
to present a realistic representation of the sample under investigation. In
addition, spectral mapping and linescans
are open to misinterpretation if overlapping peaks are present in the sum
spectrum. Finally, new aberration corrected TEMs with extremely small probe
sizes with high beam current densities can create artifacts that are generally
not experienced in microscopes with larger probes of lower beam current density.