https://doi.org/10.1007/s100510050701
Low temperature Kondo reduction of quadrupolar and magnetic moments in the YbCu5-xAlx series
1
CEA, Centre d'Études de Saclay,
DSM/Service de Physique de l'État
Condensé, 91191 Gif-sur-Yvette, France
2
Institut für Experimental Physik,
Technische Universität Wien, 1040 Wien, Austria
Received:
16
April
1998
Published online: 15 April 1999
We present measurements in
the YbCuAlx series, down to the 50 mK
range,
using 170Yb Mössbauer absorption spectroscopy and magnetisation
measurements.
In this series, the hybridisation between the Yb 4f electrons and the
conduction electrons is known to decrease as the Al content x increases.
We apply the variational solution of the impurity Kondo problem to the
interpretation of our data. We show that the Kondo temperature can be derived
from the measured 4f quadrupole moment and, for the magnetically ordered
compounds (
), we obtain the exchange energy as a function of the Al
content. Our findings are in general agreement with Doniach's model describing
the onset of magnetic ordering according to the relative values of the Kondo
and exchange energy scales.
PACS: 71.27.+a – Strongly correlated electron systems; heavy fermions / 75.30.Mb – Valence fluctuation, Kondo lattice, and heavy-fermion phenomena / 76.80.+y – Mössbauer effect; other γ-ray spectroscopy
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999