Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 46: Electronic Structure of Surfaces: Spectroscopy, Surface States
O 46.20: Poster
Dienstag, 21. März 2017, 18:30–20:30, P1A
Ab-initio investigation of the interface α-Al2O3/Al — •Lilit Amirkhanyan and Jens Kortus — TU Bergakademie Freiberg, Institute of Theoretical Physics, Germany
Ceramic materials are used in industry to remove non-metallic inclusions from metallic melts like iron or aluminum. The filtration effect depends on interactions at the interface of the ceramic filter material. Interestingly, different ceramic materials show different filtration efficiency. Therefore, a detailed understanding of the processes at the interface are of interest.
We investigated the interface of the stable phase α-Al2O3 with surface (0001). A model of the Al melt has been derived from bulk Al using the (111) plane. All calculations are based on density function theory as implemented in the Quantum Espresso code. In order to investigate the effect of oxygen or aluminum termination we carried out calculation on Al2O3 with these two terminations using the Effective Screening Medium Method with open boundary conditions. As a result we find that both terminations will give positively charged surfaces.
Further, we created interface structures and obtained from these models an interface energy. The interface energy depends on the termination of α - Al2O3. In particular, the oxygen terminated interface of α - Al2O3/Al is more stable compared to the aluminum terminated case.