Neutron scattering studies of heavy Fermions

Heavy Fermions are f electron materials characterized by a large linear term in the low temperature specific heat and a large magnetic susceptibility at low temperatures. This implies that there is a narrow peak in the f electron density of states at the Fermi energy. Typical examples are CeAl3, UBe13, CeCu2Si2, CeCu6, U2Zn17 and UPt3. Neutron scattering measurements can play an important role in understanding the magnetic interactions in these systems. Measurements of the form reveal details about the nature of the wave functions. Inelastic scattering studies gives information about the energy scale of the spin fluctuations and the narrow f-resonance. Such measurements on the above systems are reviewed with the goal of establishing systematics between the information obtained in neutron studies and that from bulk measurements.