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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 2 Issue 2 (1998) pp 169-176
Transport and thermodynamic properties of $\mathsf{CeAuAl_3 }$
S. Paschen, E. Felder, H.R. Ott (a)
Laboratorium für Festkörperphysik, Eidgenössische Technische Hochschule-Hönggerberg, 8093 Zürich, Switzerland
Received: 6 November 1997 / Accepted: 17 November 1997
Abstract: We present measurements of the specific heat, the electrical resistivity, the Hall effect, and the magnetic susceptibility of CeAuAl3, a new heavy-electron compound that crystallizes in an ordered derivative of the tetragonal BaAl4-type structure. For comparison we have also done some of these measurements on the isostructural non-magnetic reference compound LaAuAl3, which appears to be a simple metal. Below $\mbox{$T_{\mathrm{N}}$} = 1.32\:$K, CeAuAl3 orders antiferromagnetically and below 1K, we encounter Fermi liquid behaviour with considerably enhanced effective masses, i.e., a quadratic temperature dependence of the resistivity with a large prefactor and a sizable linear-in-T contribution to the specific heat. This linear-in-T contribution increases by more than a factor 50 from its value at $T\gg\mbox{$T_{\mathrm{N}}$}$ to its value at $T<\mbox{$T_{\mathrm{N}}$}$. Consequently CeAuAl3 develops a heavy-electron ground state, coexisting with antiferromagnetic order. The small energy scales involved in the problem make CeAuAl3 a good candidate for tuning it, by varying external parameters, towards a quantum critical point. At high temperatures we observe local moment behaviour. From the temperature dependence of the magnetic susceptibility and the specific heat we have derived the crystalline-electric-field-split level scheme of the J=5/2 multiplet. Distinct features in the electrical resistivity provide additional evidence for this level splitting.
PACS. 75.20.Hr Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions - 75.50.Ee Antiferromagnetics - 72.15.-v Electronic conduction in metals and alloys
(a) email: ott@solid.phys.ethz.ch
Online publication: May 5, 1998
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