Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 6: Postersession Correlated Electrons: (General) Theory, Low-Dimensional Systems, Kondo Physics, Heavy Fermions, Quantum-Critical Phenomena
TT 6.57: Poster
Montag, 23. März 2009, 13:00–16:45, P1A
11B NMR study of the low dimensional Kondo lattice YbNiB4 — •Rajib Sarkar1, Michael Baenitz1, Arpana Prasad2, Zakir Hossain2, Frank Steglich1, and Cristoph Geibel1 — 1Max-Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany — 2Department of Physics, Indian Institute of Technology, Kanpur 208016, India
YbNiB4 deserves special attention because of its interesting physical properties. Recently we reported YbNiB4 being a Kondo system with a strong 2D character, which makes this compound unique among the Yb-based systems. Two antiferromagnetic transitions show up at 5.4 K and 4.0 K [1]. Furthermore the structural homologue YbAlB4 is proposed to be a heavy Fermion system showing superconductivity at Tc=80 mK and quantum criticality without external tuning [2]. Here we present for the first time 11B NMR results on YbNiB4 as a function of temperature (2-295 K) and field. 11B NMR spectra are typical powder pattern with pronounce first order quadrupolar splitting. By lowering the temperature spectra is shifted and broadened. The observed small negative shift indicates the relevance of conduction electron polarization by the Yb 4f13 moments. Further analysis of shift as well as the spin-lattice relaxation is in progress.
[1] A. Prasad et. al., to be published,
[2] Nature Physics 4, 603(2008).