INELASTIC ELECTRON-TUNNELING SPECTROSCOPY AND XPS STUDY OF THE OXIDESGROWN ON 3 ALUMINUM-ALLOYS

Three aluminium alloys, each with different major alloying components, have been studied using inelastic electron tunnelling spectroscopy (I ETS) and XPS. The oxides grown on alloys containing magnesium and copp er have IET spectra similar to that grown on pure aluminium and their IET spectra when doped with benzoic acid also show no differences. The alloy containing silicon gives a very different IET spectrum that has band positions similar to aluminosilicates. When doped with benzoic a cid the IET spectrum of this latter alloy also shows major differences to that of benzoic acid on pure aluminium (oxide), both in band inten sities and particularly in the carboxylate stretching modes. X-ray pho toelectron spectroscopy analysis of the oxides on both the alloy thin films (IETS) and metal tokens confirms the results suggested by the IE T spectra, showing that the magnesium and copper do not appear in the oxides of the first two alloys but that silicon is present in the oxid e of the third and in quantities greater than that of the alloy compos ition.