Magnetic excitations in single crystal PrNi5

Abstract Inelastic neutron scattering has been employed to determine the crystal-field and exchange interaction in PrNi 5 . The observed energy spectra exhibit a sufficient number of well resolved crystal-field transitions, so that we have been able to unambiguously determine the four crystal-field parameters required for hexagonal symmetry. From the dispersion behavior of the lowest lying ground-state transition we determined both the nearest- and next-nearest neighbor exchange parameters to be ferromagnetic. The results allow to calculate the anisotropic exchange enhanced static susceptibility which agrees closely with corresponding experimental data. These observations are at variance with recent μSR-results which suggest that around the muon probe a large part of the susceptibility is associated with the Ni-ions.