Contribution to the study of the metal-insulator transition in the V1-xNbxO2 system—II magnetic properties

Testing the Jacob's ladder of density functionals for electronic structure and magnetism of rutileVO2

“…The likeliest interpretation of our results, in light of previous works [1,14,15], is that the observed paramagnetism of R-VO 2 arises from temperature-disordered local moments. However, an alternative interpretation is that R-VO 2 is a spin-compensated but strongly-correlated paramagnetic metal, in which the magnetic states found in DFT simply mimic the energetic effects of strong correlation [36].…”

“…Some of the FN-DMC results find a very small energy difference between FM and AFM phases, suggesting that temperature could easily disorder the spins. It is a puzzle that the observed magnetic susceptibility of R-VO 2 [1,15] does not seem to display the expected Curie-Weiss law. Perhaps in R-VO 2 below 340 K there is a thermal transition to the spin-compensated paramagnetic state.…”

“…However, the magnetic susceptibility above 340 K has no observed dependence on temperature. The data do not allow us to apply the normal Curie-Weiss law to extract the transition temperature from the paramagnetic state to the possible ferromagnetic ordering somewhere below 340 K. Pouget and coworkers [15] also measured the magnetic susceptibilities of pure VO 2 and other samples doped with various amounts of Nb. For pure VO 2 , their experimental magnetic susceptibility is the same as that of Ref.…”

LiV₂O₄: A heavy fermion transition metal oxide

“…4.9 [132] and Takigawa et al [129] respectively obtained xvv = 2.10 and 2.01 x 10-4cm3/(mol V). Kikuchi et al [133] obtained xvv = 0.92 x cm3/(mol V) for LaVO3, whereas for VO2, Pouget et al [130] obtained xw = 0.65 x 10-4cm3/(mol V).…”

LiV2O4: A Heavy Fermion Transition Metal Oxide

“…For atomic one has .4^ ^ = 403 kG [129]. We will assume that .4^^ in LiV^O^ is given [130] by that for atomic V+-'.…”