Magnesium salts and oxide: an XPS overview

XPS measurements have been performed on a series of Mg-II salts (NO3-, CO32-, SO42-, Cl-, CH3COO-), hydroxides and oxides, these latter compounds are both commercial and prepared in laboratory. The binding energy (BE) of the anionic partner in Mg-II salts compares well in any case with literature data for the same anions in other alkaline and alkaline earth compounds. The BE of Mg-II appears to be affected by the electroattractive nature of the parent anion. The Mg-II spectra, in the case of MgO samples, are not influenced either by the nature of the oxide precursor salt or by the temperature of the oxide preparation (873 K, 1073 K, 1253 K). The BE of Mg 2p ranges between 49.9 eV and 50.2 eV. Oxygen spectra are regular and show the presence of the surface chemisorbed -OH component even at heating temperatures of 1473 K. The choice, as internal reference, of the hydrocarbon contaminant carbon peak is discussed, specifically, in the case of MgO samples with reference to specific lattice and surface properties of the oxide itself. (C) 1997 Elsevier Science B.V.