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MM: Fachverband Metall- und Materialphysik
MM 3: Topical session (Symposium MM): Hydrogen in Materials
MM 3.7: Talk
Monday, March 12, 2018, 12:45–13:00, H 0107
DFT study of absorption and migration of hydrogen and oxygen in MAX phases — •Daniel F. Urban1, Francesco Colonna2, and Christian Elsässer1,2 — 1Fraunhofer IWM, Freiburg, Germany — 2University of Freiburg, FMF, Germany
MAX 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 H and O atoms in a variety of MAX-phase carbides and nitrides by means of first-principles calculations based on density functional theory. The resulting calculated formation and migration energies indicate that MAX-phase coatings can act as protective diffusion barriers for both hydrogen and oxygen, but with different migration mechanisms [1].
[1] F. Colonna, C. Elsässer, RSC Advances 7, 37852 (2017)