PHENOMENOLOGICAL THEORY OF NON-FERMI-LIQUID HEAVY-FERMION ALLOYS

We propose a phenomenological theory for heavy-fermion metallic alloys U0.2Y0.8Pd3 and UCu3.5Pd1.5 whose behavior demonstrates strong deviations from the Landau Fermi-liquid theory. The theory implies that the alloys have a critical point at T = 0 and therefore their low-temperature thermodynamics is determined not by single-particle fermion excitations, as in the Fermi liquid, but by the collective modes corresponding to fluctuations of the order parameter in the vicinity of the critical point. The observed properties are consistent with the fluctuation spectrum omega is similar to q3. Both quantum spin-glass transition and quadrupolar ordering are ruled out by the scaling analysis.