Berlin 2015 – wissenschaftliches Programm
TT 31.5: Vortrag
Dienstag, 17. März 2015, 10:45–11:00, H 2053
Phase transitions and phase separation in undoped and Rh doped CaFe2As2 — Vladimir Gnezdilov1,2, •Peter Lemmens1, Yurii Pachkevich3, Tetiana Shevtsova3, Masataka Danura4, Masakazu Kobayashi4, Tasuku Mizukami4, Kazutaka Kudo4, and Minoru Nohara4 — 1IPKM, TU-BS, Braunschweig — 2ILTPE NAS, Ukraine — 3DonFTI, Donetsk, Ukraine — 4Department of Physics, Okayama, Japan
Iron-pnictides Ca(Fe1-xRhx)2As2 (x = 0, 0.035 and 0.19) were studied across the tetragonal-orthorhombic and tetragonal collapsed tetragonal phase transitions using Raman spectroscopy. Effects of phase separation were observed in the high-temperature phase for the first time. An orbital order scenario at low temperatures for the Rh doped samples which requires a symmetry lowering down to P4/mnc or I422 without atomic displacements relative to the parent I4/mmm symmetry is discussed.
Work supported by RTG-DFG 1953/1, Metrology for Complex Nanosystems.