Berlin 2015 – wissenschaftliches Programm
TT 21.13: Poster
Montag, 16. März 2015, 15:00–18:00, Poster B
Observation of the Josephson effect on Ba-122 iron pnictide single crystals — •Noor Hasan1, Stefan Schmidt1, Sebastian Döring1, Volker Tympel1, Frank Schmidl1, Paul Seidel1, and Thomas Wolf2 — 1Friedrich-Schiller- Universität Jena , Institut für Festkörperphysik , Helmholtzweg 5, 07743 Jena, Germany — 2Karlsruhe Institute of Technology, Institut für Festkörperphysik , Hermann-von- Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
Since the discovery of the first Fe-based superconductors in 2006, extensive effort has been directed characterizing and modeling the novel properties of these exotic materials. Therefore Josephson junction offer ways to investigate the fundamental properties of iron pnictides. We use Ba(Fe1−xCox)2As2 single crystals, prepared by a self-flux method , with an optimal Co concentration of 0.065 (critical temperature Tc=23.5K) . We realize Josephson junctions along the c-axis. To prepare them a newly developed surface polishing as well as standard thin film technologies are used. The artificial barrier consists of thin sputtered layers of various materials, normal conductors as well as insulators. A thermally evaporated double layer film of Pb and In was used as the counter electrode. For the characterization of the Josephson effect we will present temperature dependent I-V characteristics as well as Ic Rn − T dependencies and measurements under microwave radiation, including. Additionally results from tunneling and Andreev spectroscopy i.e temperature dependent dI/dV - V spectra are shown.