Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 25: Correlated Electrons: Quantum-Critical Phenomena 1
TT 25.8: Talk
Wednesday, March 28, 2012, 11:30–11:45, H 3010
Ferromagnetic quantum criticality in the new heavy-fermion system YbNi4P2 — •Manuel Brando, Alexander Steppke, Stefan Lausberg, Robert Kuechler, Edit Lengyel, Lucia Steinke, Cornelius Krellner, Robert Borth, Michael Nicklas, Christoph Geibel, and Frank Steglich — Max-Planck-Institut für Chemische Physik fester Stoffe Nöthnitzer Str. 40, 01187 Dresden, Germany
We present measurements of the ac-susceptibility, specific heat (C) and thermal
expansion (α) on single crystals of the new quasi-one-dimensional heavy-fermion system
YbNi4P2.
YbNi4P2 is a Kondo-lattice system that orders ferromagnetically at a very low temperature
Tc = 0.17 K [1]. Ferromagnetism can be suppressed by arsenic substitution x on phosphorus site and
a ferromagnetic (FM) quantum critical point (QCP) is approached at x = 0.08.
We provide evidence that such a FM-QCP exists in YbNi4(P0.92As0.08)2 by showing
that (i) the magnetic transition remains ferromagnetic between x = 0 and x = 0.08,
(ii) no phase transition nor Fermi-liquid ground state down to 0.02 K can be observed at x = 0.08, and finally (iii) the Grüneisen ratio
Γ = α/C strongly diverges [2] with decreasing temperature as Γ ∼ T−0.3.
Part of this work has been supported by the DFG Research Unit 960 “Quantum Phase Transitions”.
C. Krellner et al., New J. Phys. 13 (2011) 103014
L. Zhu et al., Phys. Rev. Lett. 91 (2003) 066404