Disorder-driven non-Fermi-liquid behavior in CeRhRuSi2

We report measurements of the bulk magnetic susceptibility and Si-29 nuclea r magnetic resonance (NMR) linewidth in the heavy-fermion alloy CeRhRuSi2. The linewidth increases rapidly with decreasing temperature and reaches lar ge values at low temperatures, which strongly suggests the wide distributio ns of local susceptibilities chi(j) obtained in disorder-driven theories of non-Fermi-liquid (NFL) behavior. The NMR linewidths agree well with distri bution functions P(chi) which fit bulk susceptibility and specific-heat dat a. The apparent return to Fermi-liquid behavior observed below 1 K is manif ested in the vanishing of P(chi) as chi-->infinity indicating the absence o f strong magnetic response at low energies. Our results point out the need for an extension of some current theories of disorder-driven NFL behavior i n order to incorporate this low-temperature crossover.