[Zurück]

E.-W. Scheidt, F. Mayr, U. Killer, W. Scherer, H. Michor, E. Bauer, S. Kehrein, Th. Pruschke, F. Anders:
"Unusual non-fermi liquid of Ce_1-xLa_xNi₉Ge₄ analyzed in a single impurity Anderson model with crystal field effects";
Physica B: Condensed Matter, 378-380 (2006), S. 154 - 156.

Unusual non-fermi liquid behavior of Ce_1-xLa_xNi₉Ge₄ analyzed in a single impurity Anderson model with crystal field effects

E.-W. Scheidt a, F. Mayr a, U. Killer a, W. Scherer a, H. Michor b, E. Bauer b, S. Kehrein c, Th. Pruschke d and F. Anders e

a CPM, Inst. f. Physik, Universität Augsburg, 86159 Augsburg, Germany
b Inst. f. Festkörperphysik, TU Wien, 1040 Wien, Austria
c TP III-EKM, Inst. f. Physik, Universität Augsburg, 86135 Augsburg, Germany
d Inst. für Theo. Physik, Universität Göttingen, 37077 Göttingen, Germany
e Inst. f. Theo. Physik, Universität Bremen, 28334 Bremen, Germany

Available online 20 February 2006.

Abstract

CeNi₉Ge₄ exhibits unusual non-Fermi liquid behavior with the largest ever recorded value of the electronic specific heat Δ C/T ~=5.5JK^-2mol^-1without showing any evidence of magnetic order. Specific heat measurements show that the logarithmic increase of the Sommerfeld coefficient flattens off below 200 mK. In marked contrast, the local susceptibility Δχ levels off well above 200 mK and already becomes constant below 1 K. Furthermore, the entropy reaches 2R ln 2 below 20 K corresponding to a four-level system. An analysis of C and χ was performed in terms of an SU(N=4) single impurity Anderson model with additional crystal electric field (CEF) splitting. Numerical renormalization group calculations point to a possible consistent description of the different low-temperature scales in Δc and Δχ stemming from the interplay of Kondo effect and crystal field splitting.

Keywords: Non-Fermi liquid; Single-ion effect; Kondo physics

PACS classification codes: 71.27.+a; 75.20.Hr; 75.30.Mb

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC05938263

http://dx.doi.org/10.1016/j.physb.2006.01.263