LiV2O4: A Heavy Fermion Transition Metal Oxide

Orbital state and magnetic properties ofLiV2O4

“…Here, the former is related to the LDA DOS at the Fermi level via γ LDA =π 2 k 2 B N A D(E F )/3, and γ is the experimental value of the electronic specific heat coefficient taken from. 4 For LiV 2 O 4 we found m * /m b ≈ 25.8, which is in good agreement with previous results. 38 Such a huge enhancement of the quasi particle mass m * is a strong evidence that Coulomb correlations are important in LiV 2 O 4 and have to be taken into account in order to describe the physics of this system.…”

“…As mentioned before, a temperature dependent spin susceptibility χ(T) is observed in the temperature range from 50 to 1000 K, which fits well to the CurieWeiss law 4,7,9,10,11,12,13,15,16,17,19,20,22,23,24,25,26,27,28,29,30 χ(T)=χ 0 +C/(T-θ). However, depending on the quality of samples and experimental techniques, the values of the Curie constant C obtained from fitting the experimental data are in the range from 0.329-0.468 cm 3 K/mol.…”

“…LiV 2 O 4 exhibits a paramagnetic Curie-Weiss susceptibility 4,7,9,10,11,12,13,15,16,17,19,20,22,23,24,25,26,27,28,29,30 χ(T ) = C/(T − θ) + χ 0 in the temperature range 50-1000 K. The best fit to the experimental data is obtained under the assumption that the magnetic susceptibility χ(T ) is the sum of a Curie-Weiss and a T -independent part χ 0 , which contains Pauli paramagnetic, core diamagnetic and orbital Van Vleck contributions to the total susceptibility. 17 If all V-3d electrons (1.5 per V ion) would equally contribute to the formation of a local moment, one would expect a mixture of S = 1 and S = 1/2 vanadium ions and consequently an effective paramagnetic moment 2.34.…”

“…They also show an apparent local moment paramagnetic behavior with a strongly enhanced spin susceptibility χ at low temperatures. The discovery by Kondo et al 4 of the HF behavior in LiV 2 O 4 with a Kondo or spin fluctuation temperature T K ∼ 28 K has significant importance, because this is the first d-electron system that shows HF characteristics. Kondo et al reported a large electronic specific heat coefficient γ ≈ 0.42 J/(mol K 2 ) at 1 K, which is much larger than those of other metallic transition metal compounds like, e.g., Y 1−x Sc x Mn 2 [γ 0.2 J/(mol K 2 )] 5 and V 2−y O 3 [γ 0.07 J/(mol K 2 )].…”

Low-energy scale of the periodic Anderson model

“…CeAl 3 , CeB 6 or CeCu 6 [1], be at least qualitatively understood by a picture of independent, but coherent Kondo scatterers, with the low-energy scale set by the Kondo temperature of the dilute system. However, for UPt 3 , URu 2 Si 2 or Yb 4 As 3 [4] or the compound LiV 2 O 4 recently characterized as heavy fermion system [5] there seem to exist two distinct energy scales; one high temperature scale, T K , describing conventional incoherent Kondo scattering, and a much smaller scale, T 0 , also called coherence scale in literature, which marks the onset of Fermi liquid formation characterized by quasi particles with strongly enhanced effective masses.…”