Itinerant antiferromagnetism in the Mott compound V1.973O3.

Abstract

The doping-induced metallic state of the Mott system V{sub 2{minus}{ital y}}O{sub 3} has spin-density-wave order for {ital T}{lt}{ital T}{sub {ital N}}{approx_equal}9 K. Dynamic spin correlations in such a cation-deficient sample, V{sub 1.973}O{sub 3}, were measured with inelastic neutron scattering throughout the Brillouin zone for energies up to {approximately}20{ital k}{sub {ital B}}{ital T}{sub {ital N}} and temperatures up to {approximately}20{ital T}{sub {ital N}}. The dynamic spin-correlation function, {ital S}({ital q},{omega}), consists of a single ridge as a function of {h_bar}{omega} centered at each antiferromagnetic Bragg point. The {bold q}, {omega}, and {ital 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 {approximately}10{ital T}{sub {ital N}} are quantitatively accounted for by this theory in its simplest form with only four parameters, which are determined by our neutron-scattering experiment. {copyright} {ital 1996 The American Physical Society.}