Regensburg 1998 – wissenschaftliches Programm

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O: Oberflächenphysik

O 9: Elektronische Struktur (Experiment und Theorie)(I)

O 9.6: Vortrag

Montag, 23. März 1998, 17:30–17:45, H37

Density Functional Studies of the (010) Surface of Vanadium Pentoxide — •A. Chakrabarti¹, K. Hermann¹, R. Druzinic¹, and M. Witko² — ¹Fritz–Haber–Institut der MPG, Berlin. — ²Institute of Catalysis, PAN, Krakau (Polen).

The electronic structure of (010) oriented single layers of V₂O₅ (in a repeated slab geometry) modeling the V₂O₅ (010) surface is studied within the density functional theory (DFT) formalism. Electronic states, total energies, and atom forces (used to optimize the geometric structure) are computed with the ab initio full-potential linear augmented plane wave (FLAPW) method. A comparison of the layer results with those of the bulk shows that electronic binding between adjacent (010) single layers in V₂O₅ is rather weak in agreement with the general notion of a layer crystal. Atom relaxations inside the single layers are small suggesting minor structural rearrangements at the (010) surface as compared to the bulk termination. The computed valence densities of states (DOS) exhibit multi–peak structures which are mainly oxygen 2sp–derived (with some V 3d admixture). Further, DOS contributions from differently coordinated oxygens can be identified. The total and atom projected DOS results are compared with those of previous surface cluster calculations and yield good qualitative agreement. The theoretical valence DOS can also be compared with results from surface sensitive experiments, such as photoemission, to yield informations on the involvement of differently coordinated substrate oxygens in surface reactions.