Regensburg 2007 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 15: Phase transitions I
MM 15.2: Vortrag
Dienstag, 27. März 2007, 10:30–10:45, H4
Phonons in High-Pressure structures of Boron — •Jens Kortus1 and Lilia Boeri2 — 1TU Bergakademie Freiberg, Institut for Theoretical Physics, Leipziger Str. 23, 09599 Freiberg, Germany — 2Max-Planck Institut for Solid State Research, Heisenbergstr. 1, D-70569 Stuttgart, Germany
Boron has recently received a lot of interest in the search of new electron-phonon superconductors. Elemental boron has been shown to undergo a superconducting transition at high pressures. However, no experimental data about the actual crystal structure of the superconducting phase are available. In this work we examine the relative stability of different possible high-pressure phases of boron and calculate the phonon dispersions at the experimental pressures at which superconductivity is observed. The total-energy calculations show that the α−Ga phase of boron, which gives a metal with a low DOS, remains the most energetically favoured one up to very high pressures. Our linear-response results indicate further, that several of the in the literature proposed structures are actually unstable at high pressure.
JK would like to thank the DFG-SPP 1236 for financial support.