Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonmonotonic magnetic field dependence of remanent ferroelectric
  polarization in reduced-graphene-oxide-BiFeO$_3$ nanocomposite   In a nanocomposite of reduced graphene oxide (RGO) and BiFeO$_3$ (BFO), the
remanent ferroelectric polarization is found to follow nonmonotonic magnetic
field dependence at room temperature as the applied magnetic field is swept
across 0-20 kOe on a pristine sample. The remanent ferroelectric polarization
is determined both from direct electrical measurements on an assembly of
nanoparticles and powder neutron diffraction patterns recorded under 0-20 kOe
field. The nanosized ($\sim$20 nm) particles of BFO are anchored onto the
graphene sheets of RGO via Fe-C bonds with concomitant rise in covalency in the
Fe-O bonds. The field-dependent competition between the positive and negative
magnetoelectric coupling arising from magnetostriction due to, respectively,
interface and bulk magnetization appears to be giving rise to the observed
nonmonotonic field dependence of polarization. The emergence of Fe-C bonds and
consequent change in the magnetic and electronic structure of the interface
region has influenced the coupling between ferroelectric and magnetic
properties remarkably and thus creates a new way of tuning the magnetoelectric
properties via reconstruction of interfaces in nanocomposites or
heterostructures of graphene/single-phase-multiferroic systems.

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The categories of this paper are: astro-ph
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The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
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The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
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The categories of this paper are: econ
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph