Itinerant antiferromagnetism in the Mott compound V1.973O3

The doping-induced metallic state of the Mott system V2-yO3 has spin-density-wave order for T<T-N approximate to 9 K. Dynamic spin correlations in such a cation-deficient sample. V1.973O3. were measured with inelastic neutron scattering throughout the Brillouin zone for energies up to similar to 20k(B)T(N) and temperatures up to similar to 20T(N). The dynamic spin-correlation function, S(q.w). consists of a single ridge as a function of <(h)over bar omega> centered at each antiferromagnetic Bragg point. The q, omega. and T dependence of magnetic fluctuations can be described by the self-consistent renormalization theory for weak itinerant antiferromagnets developed by Moriya, Hasegawa, and Nakayama. Thermodynamic properties below similar to 10T(N) are quantitatively accounted for by this theory in its simplest form with only four parameters, which are determined by our neutron-scattering experiment.