Dresden 2014 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 35: Correlated Electrons: Quantum-Critical Phenomena - Experiment I
TT 35.12: Vortrag
Dienstag, 1. April 2014, 12:30–12:45, HSZ 204
Transport measurements in Yb(Rh1−xCox)2Si2 with x ≤ 0.27 — •Sandra Hamann1, Stefan Lausberg1, Christoph Klingner1, Cornelius Krellner2, Frank Steglich1, Christoph Geibel1, and Manuel Brando1 — 1Max Planck Institut for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany — 2Institute of Physics, Goethe University Frankfurt, Max-von-Laue Str. 1, 60438 Frankfurt (Main), Germany
YbRh2Si2 is considered one of the standard materials for studying quantum criticality. It shows antiferromagnetic (AFM) order below TN = 0.07 K and unconventional behavior at the magnetic-field-induced quantum critical point (QCP). Due to the low TN and the tiny size of the ordered moments (≈ 10−3µB) the exact magnetic structure could not be determined, yet. However, because of the strong magnetic anisotropy the moments are expected to lie in the ab-plane of the tetragonal crystalline structure, the magnetic easy plane. Cobalt substitution was used as chemical pressure to increase TN and the size of the ordered moments in Yb(Rh1−xCox)2Si2. Previous studies with magnetic field B ⊥ c pointed to a possible AFM groundstate for the whole series. Surprisingly, ferromagnetic order was found for x=0.27 with moments along the c-axis. This motivated a re-investigation of the groundstate for x ≤ 0.27. We present a comprehensive study of the resistivity in single crystals with x ≤ 0.27 and B ∥ c. We discuss our results considering the competition between in-plane antiferromagnetism and out-of-plane ferromagnetism and the consequences this might have for the quantum critical behavior of YbRh2Si2.