Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 53: Correlated Electrons: Heavy Fermions
TT 53.6: Vortrag
Donnerstag, 14. März 2013, 10:45–11:00, H19
Magnetic phases in Yb(Rh0.42Co0.58)2Si2 — •A. Hannaske1, O. Stockert1, C. Klingner1, C. Krellner1,2, S. Matas3, M.-H. Lemee-Cailleau4, L. Pedrero1, M. Brando1, C. Geibel1, and F. Steglich1 — 1Max-Planck-Institut CPfS, Dresden, Germany — 2Goethe-Universität Frankfurt, Frankfurt a. M., Germany — 3Helmholtz-Zentrum Berlin, Berlin, Germany — 4Institut Laue-Langevin, Grenoble, France
The heavy fermion compound YbRh2Si2, which orders antiferromagnetically below TN=70 mK, has attracted particular interest due to its anomalous properties such as pronounced non-Fermi-liquid behaviour, the divergence of the magnetic Grüneisen ratio as well as strong ferromagnetic fluctuations when approaching the quantum critical point. For a better understanding of this unique behaviour we started to investigate the microscopic magnetic structure in Yb(Rh1−xCox)2Si2. For x=1 and 0.68 we found an incommensurate propagation vector τ1≈ (0.25 0.08 1) below TN followed by a change to a commensurate structure at a lower TL with τ2= (0.25 0.25 1). Around x≈0.5, which is close to a minimum in the (x−T)-phase diagram, a change of the magnetic structure takes place. This change was investigated by a comprehensive study of magnetisation and neutron diffraction in magnetic fields on Yb(Rh0.42Co0.58)2Si2. While below TL≈700 mK the same commensurate propagation vector was found as for the higher Co concentrations, ferromagnetic behaviour was observed for TL<T<820 mK, which might be connected to the magnetic order for Co concentrations x<0.58.