NMR/mu SR and non-fermi-liquid behavior in heavy fermion systems

This paper deals with nuclear magnetic resonance (NMR) and muon spin rotati on (mu SR) experiments in heavy-fermion (HF) systems which display non-Ferm i-liquid (NFL) behavior. We review in particular our measurements in UCu5-x Pdx (x = 1 and 1.5), and discuss how these experiments have contributed to our current understanding of the role of disorder in NFL properties. Recent experiments on CeRhRuSi2 are also described. Our experiments reveal the us efulness of NMR and mu SR as ideal tools for detecting structural or intrin sic disorder and characterizing magnetic inhomogeneities in stoichiometric "ordered compounds", which appear pristine to other techniques such as X-ra ys and neutron scattering.