Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 30: Superconductivity - Poster Session
TT 30.26: Poster
Montag, 31. März 2014, 15:00–19:00, P2
High-pressure synthesis of 1111-pnictides and related systems — •Agnes Adamski1, Amir Haghighirad1,2, Steffi Hartmann1, Natalija van Well1, and Cornelius Krellner1 — 1Physikalisches Institut, Goethe University, Frankfurt am Main, — 2University of Oxford, Department of Physics, Oxford
In 2008 Kamihara et al. found a new class of high-Tc superconductors: iron-based oxypnictides. A transition temperature of 26 K in F-doped LaFeAsO (1111-compound) was reported [1]. Replacing the nonmagnetic La ion by magnetic rare-earth elements in 1111-compounds leads to an increase of the superconducting transition temperatur up to ~50 K. The crystal growth at high pressure/high temperature (HP/HT) conditions has been proven to be an effective method for the 1111-compounds [2][3].
We report on our progress to synthesize single crystals of these compounds under HP/HT conditions with a multi anvil apparatus, so called Walker-Type module. With this apparatus we can achieve rather hydrostatic pressures up to 8 GPa and temperatures up to 1750 K. We found that using NaCl/KCl as flux material is essential to avoid the formation of FeAs and to support the single crystal growth. The same Walker-Type module was used for the synthesis of related pnictides to search for new superconductors. It seems that high pressure is necessary to stabilized these compounds.
Y. Kamihara et al., J. Am. Chem. Soc. 130, 3297 (2008)
J. Karpinski et al., Physica C 469, 370 (2009)
Z. Ren et al., Adv. Mater 21, 4584 (2009)