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Practical correction formula for elastic electron scattering effects in attenuation of auger electrons and photoelectrons
Author(s) -
Jablonski A.,
Tougaard S.
Publication year - 1998
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199801)26:1<17::aid-sia343>3.0.co;2-z
Subject(s) - electron , atomic physics , elastic scattering , scattering , inelastic mean free path , photoelectric effect , electron scattering , valence electron , physics , mean free path , inelastic scattering , auger effect , chemistry , computational physics , auger , optics , quantum mechanics
We define a new parameter to describe the effects of elastic electron scattering in XPS and AES. The parameter is the ratio of emitted intensity from a layer of atoms located at a given depth in a solid calculated from theories that take into account and neglect elastic electron scattering. We have found that the correction parameter can be expressed by a simple formula. This formula is of general validity for typical experimental geometries applied in practical XPS and AES. The formula was determined by fitting an analytical expression to the results of extensive Monte Carlo calculations made under variation in the full relevant range of electron energy, matrix atomic number, depth of origin of emitted electrons and angular emission anisotropy. The formula depends on the inelastic (λ i ) and the transport (λ tr ) mean free path for electron scattering. Three assumptions were made in the calculations, namely that the geometry is close to normal emission, that the angle between x‐ray source and analyser axis is close to the magic angle (54°) and that the ratio λ tr /λ i is approximately constant over the analysed depth. However, the result is expected to vary only slightly when these assumptions are not strictly fulfilled. © 1998 John Wiley & Sons, Ltd.