Dresden 2011 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 17: SC: Fe-based Superconductors - 1111
TT 17.1: Talk
Monday, March 14, 2011, 18:15–18:30, HSZ 301
Structural trends from a consistent set of single-crystal data of RFeAsO (R = La, Ce, Pr, Nd, Sm, Gd, and Tb) — •Fabian Nitsche1, Anton Jesche2, Ellen Hieckmann3, Thomas Doert1, and Michael Ruck1,2 — 1Department of Chemistry and Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany — 2Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany — 3Institute of Applied Physics, Technische Universität Dresden, D-01062 Dresden, Germany
A new crystal growth technique for single crystals of RFeAsO (R = La, Ce, Pr, Nd, Sm, Gd, and Tb) using NaI/KI as flux is presented. Crystals with a size up to 300 µm were isolated for single-crystal X-ray diffraction measurements. Lattice parameters were determined by LeBail fits of X-ray powder data against LaB6 standard. A consistent set of structural data is obtained and interpreted in a hard-sphere model. Effective radii for the rare-earth metal atoms in RFeAsO are deduced. The relation of the intraplane and interplane distances of the arsenic atoms is identified as limiter of the phase formation, and its influence on Tc is discussed.