Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V{sub 2}O{sub 3}

Journal Article · Sun Nov 01 00:00:00 EST 1998 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.58.12727· OSTI ID:664710

Bao, W ^[1]; Broholm, C ^[2]; Aeppli, G ^[3]; Carter, S A ^[4]; Dai, P ^[5]; Rosenbaum, T F ^[6]; Honig, J M; Metcalf, P ^[7]; Trevino, S F ^[8]

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1. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)
2. Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218 (United States)
3. NEC, 4 Independence Way, Princeton, New Jersey 08540 (United States)
4. Department of Physics, University of California, Santa Cruz, California 95064 (United States)
5. Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
6. James Franck Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States)
7. Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States)
8. United States Army Research Laboratory, Adelphi, Maryland 20783 (United States)

Magnetic correlations in all four phases of pure and doped vanadium sesquioxide (V{sub 2}O{sub 3}) have been examined by magnetic thermal-neutron scattering. Specifically, we have studied the antiferromagnetic and paramagnetic phases of metallic V{sub 2{minus}y}O{sub 3}, the antiferromagnetic insulating and paramagnetic metallic phases of stoichiometric V{sub 2}O{sub 3}, and the antiferromagnetic and paramagnetic phases of insulating V{sub 1.944}Cr{sub 0.056}O{sub 3}. While the antiferromagnetic insulator can be accounted for by a localized Heisenberg spin model, the long-range order in the antiferromagnetic metal is an incommensurate spin-density wave, resulting from a Fermi surface nesting instability. Spin dynamics in the strongly correlated metal are dominated by spin fluctuations with a {open_quotes}single lobe{close_quotes} spectrum in the Stoner electron-hole continuum. Furthermore, our results in metallic V{sub 2}O{sub 3} represent an unprecedentedly complete characterization of the spin fluctuations near a metallic quantum critical point, and provide quantitative support for the self-consistent renormalization theory for itinerant antiferromagnets in the small moment limit. Dynamic magnetic correlations for {h_bar}{omega}{lt}k{sub B}T in the paramagnetic insulator carry substantial magnetic spectral weight. However, they are extremely short-ranged, extending only to the nearest neighbors. The phase transition to the antiferromagnetic insulator, from the paramagnetic metal and the paramagnetic insulator, introduces a sudden switching of magnetic correlations to a different spatial periodicity which indicates a sudden change in the underlying spin Hamiltonian. To describe this phase transition and also the unusual short-range order in the paramagnetic state, it seems necessary to take into account the orbital degrees of freedom associated with the degenerate {ital d} orbitals at the Fermi level in V{sub 2}O{sub 3}. {copyright} {ital 1998} {ital The American Physical Society}

• OSTI ID: 664710
• Journal Information: Physical Review, B: Condensed Matter, Vol. 58, Issue 19; Other Information: PBD: Nov 1998
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
VANADIUM COMPOUNDS
HEISENBERG MODEL
FERMI LEVEL
CHROMIUM COMPOUNDS
VANADIUM OXIDES
ANTIFERROMAGNETIC MATERIALS
PARAMAGNETISM
NEUTRON DIFFRACTION
CHROMIUM ADDITIONS
PHASE TRANSFORMATIONS
SPIN WAVES
CORRELATIONS