Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 79: Superconductivity: Fe-based Superconductors - 122
TT 79.2: Vortrag
Donnerstag, 10. März 2016, 15:45–16:00, H21
A light scattering study of detwinned BaFe2As2 — •Andreas Baum1,2, Milan Tomić3, Daniel Jost1,2, Ali Özkü1,2, Bernhard Muschler1, Florian Kretzschmar1,2, Thomas Böhm1,2, Nitin Chelwani1,2, Jiun-Haw Chu4,5, Ian R. Fisher4,5, Roser Valentí3, and Rudi Hackl1 — 1Walther-Meissner-Institut, 85748 Garching, Germany — 2Fakultät für Physik E23, Technische Universität München, 85748 Garching, Germany — 3Institut für Theoretische Physik, Goethe-Universität Frankfurt — 4SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA — 5GLAM and Department of Applied Physics, Stanford, University, Stanford, CA 94305, USA
The magneto-structural phase transition of BaFe2As2 is studied by Raman spectroscopy with a focus on lattice dynamics. Using uniaxial pressure to detwin the sample allows us to resolve anisotropic features. The As A1g phonon shows a resonance at high energies with distinct differences between the antiferromagnetically and the ferromagnetically ordered direction. The splitting of the Eg phonon at 130 cm−1 into two modes having B2g and B3g symmetry can be attributed to the transition into the magnetically ordered state rather than the structural transition. Both effects can be attributed to the emergence of magnetic order by DFT calculations.