Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 26: Transport - Poster Session
TT 26.33: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
First-principles study of single row Al and Pt wires — •Thomas Gnielka1,2, Klaus-Peter Bohnen1, and Rolf Heid1 — 1Forschungszentrum Karlsruhe, Institut für Festkörperphysik, D-76021 Karlsruhe — 2Universität Karlsruhe, Fakultät für Physik, D-76128 Karlsruhe
Over the past several years there has been a great deal of interest in the physical properties of atomic wires. Although there have been some studies of the structural and electronic properties of nanowires so far lattice dynamics of these systems has been hardly studied. This is in strong contrast to the importance of lattice dynamics for structural stability (Peierls transition) and superconductivity. Thus we have investigated the lattice dynamics, the atomic and electronic structures and the relation between them for single-row Al and Pt wires using density-functional theory. The calculations reveal that the wires transform from planar zigzag structure to linear and further to dimerized wires during elongation. Phonon dispersions have been calculated and anomalies nicely correlate with Fermi surface nesting effects. Dimerization effects as seen for Pt wires on Ge(100) seem to be qualitatively in agreement with these findings, however the substrate influence has still to be studied. Prelimenary results seem to indicate the importance of substrate effects.