X-ray K absorption discontinuities of Cr and Fe

The structures of the K absorption discontinuities of the 3d transition elements illustrated by previous researchers have been studied and comments on the assignments given by them for the electronic transitions corresponding to the various parts of the discontinuities have been made. The K absorption spectra of Cr and Fe in the metals and oxides were then observed, and having found small absorption humps on the long-wavelength side of the main discontinuities in the spectra of the metals revised assignments for the transitions in the absorption processes are presented. Further, the shifts of the K absorption limits of these elements caused by chemical combination are presented, referring to a proposition presented previously by the authors (1973).