Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electric field control of multiferroic domains in Ni$_3$V$_2$O$_8$
  imaged by X-ray polarization enhanced topography   The magnetic structure of multiferroic Ni$_3$V$_2$O$_8$ has been investigated
using non-resonant X-ray magnetic scattering. Incident circularly polarized
X-rays combined with full polarization analysis of the scattered beam is shown
to yield high sensitivity to the components of the cycloidal magnetic order,
including their relative phases. New information on the magnetic structure in
the ferroelectric phase is obtained, where it is found that the magnetic
moments on the "cross-tie" sites are quenched relative to those on the "spine"
sites. This implies that the onset of ferroelectricity is associated mainly
with spine site magnetic order. We also demonstrate that our technique enables
the imaging of multiferroic domains through polarization enhanced topography.
This approach is used to image the domains as the sample is cycled by an
electric field through its hysteresis loop, revealing the gradual switching of
domains without nucleation.

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The categories of this paper are: math
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The categories of this paper are: hep-th
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The categories of this paper are: physics
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The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: hep-lat