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Quasi one dimensional material NaV2O4 is a newly fabricated material consisting of zigzag chains of VO6 octahedra,
where vanadium ions have a nonintegral valence V+3.5 (3d1.5).
Because of the structural anisotropy [see right figure (b) and (c)],
the resistivity along the chains ρb is an order of magnitude smaller
than that transverse to the chains ρac at room temperature
with a noticeable downturn in ρb below a magnetic transition temperature at T=140K.
Despite the quasi-one-dimensional nature, this system does not show any other instability against
either a spin density wave or a charge density wave,
and the metallic conductivity along the chain direction is well preserved;
ρac/ρb becomes even larger than 20 at low temperature.
These unique transport properties as well as magnetic properties can be readily understood by a model
in which the integer magnetic moments order ferromagnetically along the
chains, with the chains coupled antiferromagnetically.
This work was done by Satoshi Okamoto in collaboration with Correlated Electron Materials Group at ORNL,
National Institute for Materials Science (Japan), Louisiana State University, and Los Alamos National Laboratory.
Phys. Rev. Lett. 99, 196601 (2007).
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