Heavy Fermion Behaviors in LiV_{2}O_{4}
Experiments of various types on the metallic transition metal oxide compound LiV_{2}O_{4} with the fcc normal-spinel structure are reviewed. The low-temperature T < 10 K data consistently indicate heavy fermion (HF) behaviors characteristic of those of the heaviest-mass f-electron HF compounds. A crossover is observed above about 50 K in the magnetic susceptibility, ^{7}Li spin-lattice relaxation rate and neutron magnetic scattering function to a magnetic state variously described as an antiferromagnetically-coupled local-moment metal or, at the opposite extreme, as an itinerant nearly-ferromagnetic metal. Recent theoretical investigations to understand these properties of LiV_{2}O_{4} are discussed.