Use of an Auger parameter for characterizing the Mg chemical state in different materials

Abstract

Metallic, oxide and hydroxide environments of magnesium are clearly identified by X-ray photoelectron spectroscopy from chemical shift of Mg 1s and Mg 2p photopeaks. Unfortunately, Mg 3 N 2 cannot be distinguished from MgO through these two peaks. In this work, we give evidence that it is possible to unambiguously identify magnesium nitride from magnesium oxide thanks to a Mg Auger parameter defined as the difference between the kinetic energy (KE) of the Mg K L L Auger peak and the KE of the Mg 1s peak. The value obtained for Mg 3 N 2 (1000.0 eV) is quite different from the one observed for MgO (998.6 eV). Values obtained for metallic Mg and for Mg(OH) 2 are, respectively, equal to 1004.2 and 997.5 eV. This parameter is then used in order to characterize the modification of the Mg chemical environment in the Al-5083 aluminum alloy (containing 4.5 at.% Mg) nitrided by a distributed electron cyclotron resonance nitrogen plasma.