XTI. On the fine structure near the FeK-absorption edges in the various oxides of Fe

Summary After a review of the theoretical interpretation of the fine structure in X- ray absorption edges, new measurements on the K-edges of different compounds of iron at low dispersion are described. From these in conjunction with our earlier measurements at high dispersion (Coster and Kiestra 1948) the following conclusions may be drawn with respect to these compounds. a. (a) In a region up to about 70 eV. from the edge the behaviour of the absorption coefficient is mainly a property of the atom in question.b. (b) In a region between 70 and 175 eV. the fine structure is determined by the immediate surroundings of the atom.c. (c) In the region above 175 eV. the fine structure depends essentially on the crystal lattice. This is in accordance With the notion that as the energy of the ejected electron increases it penetrates further into the lattice.