Publications in Scientific Journals:

E.-W. Scheidt, U. Killer, H. Michor, E. Bauer, C. Dusek, S. Kehrein, W. Scherer:
"Crossover from single ion to coherent non-Fermi liquid behavior in Ce1-xLaxNi9Ge4";
Physica B: Condensed Matter, 359-361 (2005), 254 - 256.

English abstract:
Crossover from single ion to coherent non-Fermi liquid behavior in Ce1-xLaxNi9Ge4

E.-W. Scheidt a, U. Killer a, H. Michor b, E. Bauer b, C. Dusek b, S. Kehrein c and W. Scherer a

a Chemische Physik und Materialwissenschaften, Institut fur Physik, Universität Augsburg, 86159 Augsburg, Germany
b Institut für Festkörperphysik, TU Wien, 1040 Wien, Austria
c TP III, Elektronische Korrelationen und Magnetismus,Universität Augsburg, 86159 Augsburg, Germany

Available online 5 February 2005.


We report specific heat and magneto-resistance studies on the compound Ce1-xLaxNi9Ge4 for various concentrations over the entire stoichiometric range. Our data reveal single-ion scaling with Ce-concentration between x=0.1 and 0.95. Furthermore, CeNi9Ge4 turns out to have the largest ever recorded value of the electronic specific heat Δ c/T ~ 5.5 J K-2 mol-1 at T = 0.08 K which was found in Cerium f-electron lattice systems. In the doped samples Δ c/T increases logarithmically in the temperature range between 3 K and 50 mK typical for non-Fermi liquid (nFl) behavior, while ρ exhibits a Kondo-like minimum around 30 K, followed by a single-ion local nFl behavior. In contrast to this, CeNi9Ge4 flattens out in Δ c/T below 300 mK and displays a pronounced maximum in the resistivity curve at 1.5 K indicating a coherent heavy fermion groundstate. These properties render the compound Ce1-xLaxNi9Ge4 a unique system on the borderline between Fermi liquid and nFl physics.

Keywords: Non-Fermi liquid; Heavy fermion; Single ion effect

PACS: 71.27.+a; 71.10.Hf; 75.30.Mb

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Created from the Publication Database of the Vienna University of Technology.