Experimental evidence for predicted universal behavior in low-temperature Kondo lattices

We have previously shown that the 1/N expansion of the Kondo lattice leads to the following predictions concerning the heavy-Fermi-liquid state: (i) the low-temperature specific heat behaves as Cᵥ=_γT∝TT̄ₖ with corrections ΔCᵥ=(TT̄ₖ)³In(TT̄ₖ), (ii) the zero-temperature spin susceptibility χ∝1T̄ₖ, and (iii) the resistivity ρ∝(TT̄ₖ)². These results all contain a unique energy scale T̄ₖ. Here we analyze recent pressure-dependent specific-heat measurements on UPt₃ combined with χ and ρ data to confirm the scaling of these quantities with one strongly pressure-dependent energy scale γ^-1. This picture is further supported by evidence of systematic scaling of χ and ρ with γ throughout the entire class of heavy-fermion compounds. This behavior, along with other experimental observations, suggests that the low-T properties of UPt₃ do not derive from ferromagnetic spin fluctuations.