Self-assembled Pt nanowires on Ge(001): Relaxation effectsU. Schwingenschlögl and C. Schuster
Institut für Physik, Universität Augsburg - 86135 Augsburg, Germany
received 19 September 2007; accepted in final form 7 November 2007; published January 2008
published online 3 December 2007
Absorption of Pt on the Ge(001) surface results in stable self-organized Pt nanowires, extending over some hundred nanometers. Based on band structure calculations within density functional theory and the generalized gradient approximation, the structural relaxation of the GePt surface is investigated. The surface reconstruction pattern obtained agrees well with findings from scanning tunneling microscopy. In particular, strong PtPt dimerization is characteristical for the nanowires. The surface electronic structure is significantly perturbed due to GePt interaction, which induces remarkable shifts of Ge states towards the Fermi energy. As a consequence, the topmost Ge layers are subject to a metal-insulator transition.
68.43.Bc - Ab initio calculations of adsorbate structure and reactions.
73.20.-r - Electron states at surfaces and interfaces.
73.20.At - Surface states, band structure, electron density of states.
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