Phase Stability and Initial Oxidation of Ti2AlC Thin Films at 500 °C
(English)Manuscript (preprint) (Other academic)
Ti2AlC thin films deposited onto Al2O3 by magnetron sputtering have been annealed in vacuum and ambient air. The films consist of basal-plane-oriented grains with a fraction of nonbasal-plane-oriented grains with an out-of-plane orientation of  and  as shown by x-ray diffraction and scanning electron microscopy. The surface of the basalplane-oriented grains has (0001) terraces growth. In situ x-ray diffraction shows that the Ti2AlC phase decomposes during vacuum annealing at 700 °C, which is lower than what have been reported for bulk material. When oxidized in ambient air at 500 °C for 5 min oxide clusters of amorphous Al2O3 form in valleys between terraces. The oxides are formed by out-diffusion of Al along the basal planes and migration over the surface. X-ray photoelectron spectroscopy of a Ti2AlC film oxidized at 500 °C for 15 min shows oxides due to a parallel oxidation of Ti and Al.
IdentifiersURN: urn:nbn:se:liu:diva-57521OAI: oai:DiVA.org:liu-57521DiVA: diva2:326283