Sm. Thurgate et al., APPLICATIONS OF AUGER-PHOTOELECTRON COINCIDENCE SPECTROSCOPY (APECS) TO UNDERSTANDING INNER-SHELL TRANSITIONS, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 87(1-4), 1994, pp. 259-266
Auger electron spectroscopy (AES) is widely used as a means of quantit
ative surface analysis. The Auger decay process is complex, involving
at least three electrons. Often there are a number of competing decay
channels open which result in complex spectral features. Transition ra
tes into these channels can depend on quantities like the valence band
width that can be determined by the chemical environment and the crys
talline structure. APECS is a means of simplifying Auger spectra. In a
n APECS spectrum, Auger electrons are only counted when a photoelectro
n is collected in coincidence. This has a number of consequences. The
origin of the Auger ionisation is known, only those features due to th
e particular ionisation are present and the mean free path (MFP) of th
e collected electron is smaller than if collected in the standard, sin
gles mode. This means that the origins of particular spectral features
can be identified and comparison between theory and experiment can be
made more readily. Several examples of how APECS has been used to stu
dy the LVV spectra of a number of 3d transition metals are presented.
An analysis of the deformation in line shape that occurs when data is
collected in coincidence is also presented.