Dresden 2011 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 42: SC: Fe-based Superconductors - Fe(Se,Te)
TT 42.2: Vortrag
Mittwoch, 16. März 2011, 19:00–19:15, HSZ 304
Superconducting FeSe0.5Te0.5 under high pressure: Susceptibility, XRD and Mössbauer studies. — •Vadim Ksenofontov1, Leslie Schoop1, Sergey Medvedev2, Michail Eremets2, Vladimir Tsurkan3, Joachim Deisenhofer3, Alois Loidl3, Gerhard Wortmann4, and Claudia Felser1 — 1Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg - University, Mainz, Germany — 2Max-Planck-Institute for Chemistry, Mainz, Germany — 3Institute of Physics, University of Augsburg, Augsburg, Germany — 4Department of Physics, University of Paderborn, Paderborn, Germany
High-pressure magnetic, structural and Mössbauer studies were performed on single-crystalline samples of superconducting (sc) FeSe0.5Te0.5 with Tc = 14.5 K [1]. Susceptibility data up to 1.5 GPa revealed a strong increase of Tc up to 25 K, followed by a plateau in Tc up to 6.0 GPa. Further increase of pressure leads to a disappearance of sc state around 7.0 GPa. Structural and Mössbauer studies explain this fact by a structural phase transition of the sc PbO to the non-sc NiAs structure. We discuss the fact of an almost pressure-independent Tc, between 1.5 and 6.0 GPa by the respective variation of the lattice constants and hyperfine parameters in FeSe [2]. We conclude that the strong increase of Tc in FeSe0.5Te0.5 with pressure up to 1.5 GPa can not be attributed to a change in the phonon-DOS [3].
V. Tsurkan et al., arXiv:1006.4453.
S. Medvedev et al., Nature Mater. 87, 630 (2009).
V. Ksenovontov et al., Phys. Rev. B 81, 184510 (2010).