Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 20: SC: Fabrication and Characterization of Iron-Based and Other Superconductors

TT 20.3: Vortrag

Mittwoch, 24. März 2010, 10:00–10:15, H19

Single crystal growth and physical characterization of íron-pnictides Ca(Fe_1−xCo_x)₂As₂ — •Luminita Harnagea, Surjeet Singh, Gerd Friemel, Norman Leps, Friedrich Roth, Mahmoud Abdel-Hafez, Ulrike Stockert, Sabine Wurmehl, Günter Behr, Christian Hess, Rüdiger Klingeler, Martin Knupfer, and Bernd Büchner — Leibniz Institute for Solid State Materials Research (IFW) Dresden, Germany

Single crystals of iron-pnictides Ca(Fe_1−xCo_x)₂As₂ (0≤ x≤0.2) were grown from Sn-flux using the conventional high temperature solution growth technique. All the grown crystals were found to be phase-pure crystallizing in a tetragonal ThCr₂Si₂-type structure. In particular, no trace of Sn incorporation in the structure was detected. Upon Co doping, the c-crystallographic axis of the tetragonal unit cell decreases, while a-axis shows a less significant variation. Crystals were plate-like exhibiting lateral dimensions up to 15 mm and 0.5 mm thick. The details of crystal characterization, including the chemical composition, growth habits and morphology of the grown crystals are presented. Effects of Co-doping on the structural/magnetic transition of CaFe₂As₂ are discussed from optical spectroscopy and temperature dependent resistivity and susceptibility studies.