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O: Oberflächenphysik
O 25: Epitaxie und Wachstum II
O 25.8: Vortrag
Dienstag, 9. März 2004, 17:30–17:45, H39
Continuous Phase Transition of Surface Reconstructions Investigated by X-ray Scattering: Theory and Experiment — •Frank Grosse1, Bernd Jenichen2, Wolfgang Braun2, Vladimir M. Kaganer2, Dilip K. Satapathy2, X. Guo2, and Klaus H. Ploog2 — 1Institut für Physik der Humboldt-Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany — 2Paul-Drude-Institut für Festkörperelektronik Hausvogteiplatz 5-7, 10117 Berlin, Germany
Atomistic simulations for the reconstruction transition on the InAs(001) surface are performed on the basis of ab initio density functional calculations [1]. A continuous surface phase transition of the As-rich β2(2×4) reconstruction to the α2(2×4) reconstruction is predicted leading to a mixture of both reconstructions. The atomic coordinates of the simulation cells are used to calculate the X-ray diffraction intensity employing kinematic theory. The equilibrium properties and kinetic effects due to change in temperature as well as As-pressure are discussed. Experiments performed at BESSY (Berlin) allow an in situ measurement and structure analysis of the reconstruction phase transition and are in agreement with the theoretical predictions. [1] F. Grosse, W. Barvosa-Carter, J.J. Zinck, M. Wheeler, and M.F. Gyure. Phys. Rev. Lett. 89, 116102 (2002); F. Grosse and M. Gyure. Phys. Rev. B. 66, 075320 (2002).