Berlin 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 8: Superconductivity: Fe-based Superconductors - 122 Part 1

TT 8.8: Vortrag

Montag, 26. März 2012, 17:00–17:15, H 2053

Calorimetric evidence of multiband superconductivity in A_1−xNa_xFe₂As₂ (A = Ba and Ca) single crystals — •Mahmoud Abdel-Hafiez, Saicharan Aswartham, Dirk Bombor, Luminita Harnagea, Manoj Kumar, Ashim Pramanik, Volodymr Zabolotnny, Vladislav Kataev, Christian Hess, Sabine Wurmehl, Anja U. B. Wolter, and Bernd Büchner — Leibniz Institute for Solid State and Materials Research IFW Dresden, 01069 Dresden, Germany

We report on the electronic properties and the superconducting gap characteristics of superconducting single crystals of A_1−xNa_xFe₂As₂ (A = Ba and Ca) studied by low temperature specific heat measurements. The zero-field specific heat data manifests a high electronic specific heat in the normal state, which is comparable to other holedoped 122 compounds. We demonstrate that the measured zero field temperature dependence of the specific heat can be well described by two s-wave gaps. This is further confirmed by the scaling based on the s-wave and d-wave scenario of the low temperature data at various magnetic fields. Our results are qualitatively similar to other holedoped 122 compounds, but nevertheless the magnitude of the gaps and their ratio are quite different.