Evidence for Low Temperature Singlet Ground State in the Dense Kondo System

Abstract

Heat capacity measurements performed on CeAl3 between 1.8 and 300K indicate pronounced anomalies near 5 and 25K. Neutron diffraction measurements down to 3.5K revealed the absence of any magnetic ordering in CeAl3. The results have been interpreted on the basis of the combined effects of crystal field splitting and the Kondo effect on the Ce3+ ions. Analysis of the measured entropy leads to the conclusion that the low temperature ground state in this Kondo system is a spin and orbit compensated singlet, in accord with recent theoretical predictions.