Auger electron spectroscopy of the air-exposed (Cr$_{0.5}$Mn$_{0.5}$)$_2$GaC MAX film surface

We have analyzed chemical bonding of atmospheric oxygen with chromium and manganese on the epitaxial MAX-phase (Cr$_{0.5}$Mn$_{0.5}$)$_2$GaC surface using Auger electron spectroscopy combined with ion etching. It was found that the system has a specific anisotropic oxidation where oxygen atoms bind to chromium and manganese ones more actively at the faces of layered MAX phase crystallites in contrast to the (0001) basal plane. At the same time, the dominance of the Mn–O chemical bonding over Cr–O is observed on the latter.