Charge ordering and opening of spin gap in NaV2O5

1998/06/18 by Maxim Mostovoy, M.V. Mostovoy, Daniel Khomskii +1 · 8 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Transition Metal Oxide Nanomaterials #cond-mat

paper · pdf · doi:10.1016/s0038-1098(99)00453-6

5 pages, revtex, epsf, 3 Postscript figures

arxiv created 1998/06/18 · openalex publication_date 1999/12/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We suggest that the phase transition observed in NaV₂O₅ at T_c = 34K is not a spin-Peierls transition, but a charge ordering transition, related to the formal presence in this system of equal number of V⁴+ and V⁴- ions. Below T_c, V⁴+ ions form a zigzag structure, which is consistent with the experimentally observed doubling of the lattice period in a and b directions. We show that this charge ordering also results in the alternation of spin exchange constants along the b-direction, which opens a gap in the spin excitation spectrum. We emphasize the role of lattice distortions around V ions both in the formation of the charged ordered state and in the spin-gap opening.

Citations

• High-frequency dielectric and magnetic anomaly at the phase transition inNaV2O5

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