Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.56: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
Thermal Transport Properties of the Heavy Fermion Compound YbRh2Si2 — •Stefanie Hartmann1, Ulrike Köhler1, Niels Oeschler1, Cornelius Krellner1, Christoph Geibel1, Samuel Maquilon2, Zachary Fisk2, and Frank Steglich1 — 1Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany — 2Department of Physics, University of California, Davis, CA 95616, USA
The heavy-fermion compound YbRh2Si2 orders antiferromagnetically at TN = 70 mK and reveals non-Fermi-liquid (NFL) behavior in the vicinity of a (magnetic field induced) quantum critical point (QCP).
Thermal conductivity κ and thermopower S measurements on high-purity single-crystalline samples of YbRh2Si2 as well as of the nonmagnetic reference compound LuRh2Si2 in the temperature range between 30 mK and room temperature are presented and discussed within the framework of current theoretical models.
The high temperature transport properties are dominated by the transition from incoherent to coherent Kondo scattering and furthermore by the crystal electric field splitting of the Yb3+ ions, as the first excited doublet is situated at 200 K. The low temperature regime is governed by the strong NFL behavior due to the proximity of the antiferromagnetic instability.