New method for quantitative analysis by ESCA.

It is shown that empirical sensitivity factors do not provide a reliable basis for quantitative chemical analysis by ESCA, because the fraction of photoelectic events accompanied by intrinsic excitations depends on the electronic structure of the solid. It is pointed out that the area of the entire photoemission line, including the loss tail, is directly proportional to the photoelectric cross section, and can sometimes be advantageously used for quantitative analysis. This method has the advantages of being largely insensitive to surface segregation and surface contamination.