Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 25: FS: Iron-Based Superconductors
TT 25.9: Vortrag
Mittwoch, 24. März 2010, 17:45–18:00, H20
Mössbauer high pressure and magnetic field studies of the superconductor FeSe — Vadim Ksenofontov1, Gerhard Wortmann2, Ivan Trojan3, Taras Palasyuk3, Sergey Medvedev3, Michail Eremets3, Tyrel M. McQueen4, Richard J. Cava4, and •Claudia Felser1 — 1Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg - University, Mainz, Germany — 2Department of Physics,University of Paderborn, Paderborn, Germany — 3Max-Planck-Institute for Chemistry, Mainz, Germany — 4Department of Chemistry, Princeton University, Princeton, USA
Superconducting FeSe has been investigated by Mössbauer spectroscopy applying high pressure and strong external magnetic fields. It was found that pressure-induced structural phase transition between tetragonal and hexagonal modifications is accompanied by increased distortion of local surrounding of Fe atoms. Appearance of the hexagonal phase above 7.2 GPa is accompanied by degradation of superconducting properties of FeSe. Low-temperature measurements demonstrated that the ground states in both orthorhombic and hexagonal phases of FeSe are nonmagnetic. Mössbauer measurements in the external magnetic field below transition to the superconducting state revealed zero electron spin density on Fe atoms. Interpretation of Mössbauer spectra of FeSe in the Shubnikov phase is discussed.