Neutron scattering studies of heavy fermion systems (invited) (abstract)

摘要

We review our results of neutron scattering experiments on the heavy electron systems UPt3, U2Zn17, and URu2Si2. In the superconductor UPt3we have established the existence of spin fluctuations on an energy scale of 0.5 meV and correlated in the same structure as the antiferromagnetic order in the Th‐ and Pd‐doped systems. In the antiferromagnet U2Zn17overdamped antiferromagnetically correlated excitations dominate the excitation spectrum above and belowTN. However, in an applied field the resonances are induced in the transverse response. In the antiferromagnetic superconductor URu2Si2the excitations in the ordered phases are propagating, longitudinal and similar to observations in singlet rare‐earth ground‐state systems. However, the ordered moment of 0.03mgr;Bis anomalously small and the transverse response is overdamped. We discuss a simple model of exchange coupled overdamped responses which gives a consistent description of the diffusive spin‐fluctuations in several heavy electron systems.