XPS is the spectroscopy of photoelectrons ejected out of a unknown sample exposed to x-ray radiation. XPS is also known as ESCA (electron spectroscopy for chemical analysis) and can be used to determine the composition and actual chemical state of surfaces.With this spectroscopy method it is possible to characterize a surface according to the sort of element present and in which oxidation state it exists. With the help of a ion-gun depth profiling is possible in an alternating sputter-XPS measurement process. This delivers information about the composition of a surface in different depths.
Auger-Spectroscopy (named after French physicists Pierre Auger) is a complementary method to XPS spectroscopy. The sample is irradiated by an electron beam of well known energy. Due to this bombardment the surface under investigation itself ejects Auger electrons, which can be analysed according to their energy. As result the composition of the surface can be determined. In contrary to XPS, the Auger spectroscopy is most sensitive for the lighter elements, so that XPS and AES can be perfectly combined to get most sample information possible. The XPS spectrometer at Limedion consists of a transfer system, sample manipulator, x-ray gun (Al/Mg), Ion gun for depth profiling (not pictured), electron-gun.