Colonna, F.F.ColonnaElsässer, C.C.Elsässer2022-03-052022-03-052017https://publica.fraunhofer.de/handle/publica/24953710.1039/C7RA05045CMAX phases are ternary metal carbides and nitrides with multi-layered crystal structures and mixed metallic-covalent bonding. They have very good thermal, chemical, and mechanical properties which make them potentially suitable as corrosion protection coatings for high-temperature energy-conversion devices such as solid oxide fuel cells. To assess the capability of MAX phases as diffusion barriers for hydrogen and oxygen, we investigate absorption and migration of interstitial H and O atoms in the MAX phase Ti2AlN by means of first-principles calculations based on density functional theory. The resulting calculated formation and migration energies indicate that a Ti2AlN coating can act as a protective diffusion barrier for both oxygen and hydrogen, but according to two different mechanisms.enMAX phaseTi2AlNdensity functional theorydiffusionhydrogenoxygentransition state theoryjournal article