Regensburg 2016 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 78: Correlated Electrons: Poster Session

TT 78.9: Poster

Donnerstag, 10. März 2016, 15:00–18:30, Poster D

Unusual antiferromagnetic structure of YbCo₂Si₂ — N. Mufti^1,2, K. Kaneko^1,3, A. Hoser⁴, M. Gutmann⁵, C. Geibel¹, C. Krellner^1,6, and •O. Stockert¹ — ¹Max-Planck-Institut für Chemische Physik fester Stoffe, Dresden — ²Department of Physics, State University of Malang, Malang, Indonesia — ³Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Japan — ⁴Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin — ⁵ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot, United Kingdom — ⁶Physikalisches Institut, Goethe-Universität Frankfurt, Frankfurt

We report on extensive powder and single crystal neutron diffraction experiments to study the magnetic structure in YbCo₂Si₂ below the Néel temperature T_N = 1.7 K in detail. Representation analysis has been used to find the possible magnetic structure models compatible with the experiments. Two different magnetically ordered phases can clearly be distinguished. At lowest temperatures a commensurate magnetic structure with a propagation vector k₁ = (0.25  0.25  1) and equal moments or about 1.4 µ_B/Yb is found, while the intermediate phase (T > 0.9 K) is characterized by an incommensurate amplitude-modulated magnetic structure with k₂ = (0.25  0.086  1). The magnetic structure in YbCo₂Si₂ is in stark contrast to all other compounds of the RCo₂Si₂ family (R = rare earth element) likely due to some itineracy of the Yb 4f states being responsible for the magnetism.