Dresden 2003 – wissenschaftliches Programm
O 12: Postersitzung (Struktur und Dynamik reiner Oberfl
äche fest-flüssig, Nanostrukturen, Teilchen und Cluster, Halbleiteroberfl
ächen und Grenzfl
ächen, Zeitaufgelöste Spektroskopie, Rastersondentechniken, Methodisches)
O 12.49: Poster
Montag, 24. März 2003, 18:00–21:00, P1
Atomic scale imaging and electronic structure of the MoO2 (100)-surface — •Judith Moosburger-Will1, Matthias Klemm1, Philip Hofmann2, and Siegfried Horn1 — 1Institut für Physik, Universität Augsburg, 86159 Augsburg, Germany — 2Institute for Storage Ring Facilities, University of Aarhus, DK-8000 Aarhus C, Denmark
The investigation of the structure of oxide surfaces, like that of TiO2 and VO2, are of great interest for the field of catalysis. We investigated the (100)-surface of single crystals of the structurally related metallic MoO2 by low energy electron diffraction (LEED) and by scanning tunneling microscopy (STM). Heating in situ up to 750 ∘C provides a clean surface with a long range atomic order. Both STM images and LEED pattern show a surface consistent with the termination expected from the bulk lattice structure. After a more intense heat treatment a (4 x 1) reconstruction is observed by LEED. The STM images of this reconstructed surface display well distinguished rows of atoms. The distance between rows corresponds to the lattice parameter determined from LEED. A similar reconstruction was found for VO2  and the effect was attributed to the removal of rows of oxygen. The results of photoelectron emission measurements taken of the unreconstructed and reconstructed MoO2 (100)-surface are discussed and compared to the calculated band structure.
 Goering et al., Phys. Rev. B 55, 4225 (1997).