Eur. Phys. J. B 8, 363-369 (1999)
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

Abstract

We present measurements in the YbCuAl_x 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.