Crystal field in the heavy fermion compound CeAl3

Abstract

We present the results of an analysis of inelastic neutron scattering data on CeAl3. By combining the neutron scattering results with measurements of the single-crystal magnetic susceptibility, we have obtained an unambiguous set of crystal field parameters in CeAl3. A comparison of the crystal field parameters along the RAl3 (R=Ce, Pr, and Nd) series of isostructural compounds shows that in CeAl3, A20〈r2〉 is an order of magnitude larger, and A40〈r4〉 is three times larger, than in PrAl3 and NdAl3. These increases cannot be explained by changes in lattice parameters but are more likely to result from the enhancement of the hybridization of the cerium 4f electrons with the conduction electrons in CeAl3. This conclusion is in agreement with the results of our study of the RCu2Si2 series.