Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Charge Ordering and Phase Competition in the Layered Perovskite
  Lasr2mn2o7   Charge-lattice fluctuations are observed in the layered perovskite manganite
LaSr2Mn2O7 by Raman spectroscopy as high as 340 K and with decreasing
temperature they become static and form a charge ordered (CO) phase below
TCO=210 K. In the static regime, superlattice reflections are observed through
neutron and x-ray diffraction with a propagation vector (h+1/4,k-1/4,l).
Crystallographic analysis of the CO state demonstrates that the degree of
charge and orbital ordering in this manganite is weaker than the charge
ordering in three dimensional perovskite manganites. A TN=170K a type-A
antiferromagnetism (AF) develops and competes with the charge ordering, that
eventually melts below T*=100K. High resolution diffraction measurements
suggest that that CO- and AF-states do not coincide within the same region in
the material but rather co-exist as separate phases. The transition to type-A
antiferromagnetism at lower temperatures is characterized by the competition
between these two phases.

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The categories of this paper are: nucl-ex
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The categories of this paper are: math
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int