Abstract
The X-ray Lα 1, 2 emission spectra and LIII absorption spectra in Cu, Cu2O, CuCl, Cu2S, CuO, CuCl2, CuS, CuF2 and Cu(en)2Cl2 are investigated. It is shown that the emission spectra of divalent copper compounds are considerably distorted due to a sharp absorption peak near the LIII edge. The nature of this peak is discussed and a relation is made with satellite peaks in X-ray photoelectron spectra.