Determination of co-ordination number in some compounds of magnesium and aluminium: a comparison of X-ray photoelectron (ESCA) and X-ray emission spectroscopies

Abstract

The effect of changes in co-ordination number (four to six, oxygen ligands) upon 2p and 2s ionisation energies of magnesium and aluminium is shown to be about ten times greater (i.e. ca. 2 eV) than the effect upon the Kα emission energy, X-ray photoelectron spectroscopy (ESCA) is therefore to be preferred to X-ray emission spectroscopy for the determination of co-ordination number; at constant co-ordination number orbital energies are also affected by the nature of the ligands.