First evidence for a Sm\(^{3+}\)-type contribution to the magnetic form factor in the quasielastic spectral response of intermediate valence SmB\(_{6}\)

The momentum transfer dependence of the magnetic form factor associated with the quasielastic spectral component in the dynamic magnetic response of intermediate valence SmB\(_{6}\) has been measured using inelastic neutron scattering on a double-isotope (\(^{154}\)Sm, \(^{11}\)B) single crystal. The experimental dependence differs qualitatively from those obtained earlier for the inelastic signals, as well as from the field-induced magnetic form factor of SmB\(_{6}\) obtained by polarized neutron diffraction. This observation is interpreted by specifically considering the Curie-type contributions to the dynamic susceptibility, which arise from the mixing of 4f\(^{5}\) and 4f\(^{6}\) J-multiplets into the intermediate valence state wave function.