LiV2O4: A Heavy Fermion Transition Metal Oxide

A crossover with decreasing temperature T from localized moment magnetism to heavy Fermi liquid behavior is reported for the metallic compound LiV2O4 with the fcc normal-spinel structure. At T=1 K, the electronic heat capacity coefficient γ≈0.42 J/mol K2 is exceptionally large for a transition metal compound, the Wilson ratio ≈1.7, and the Korringa ratio ≈0.7. Our sample with the lowest level of paramagnetic defects showed no static magnetic order above 0.02 K. Superconductivity was not observed above 0.01 K.