Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase diagram and magnetic properties of La$_{1-x}$Ca$_x$MnO$_3$
  compound for $0\leq x \leq 0.23$   In this article a detailed study of La$_{1-x}$Ca$_x$MnO$_3$ ($0\leq x \leq
0.23$) phase diagram using powder x-ray diffraction and magnetization
measurements is presented. Unfortunately, in the related literature no properly
characterized samples have been used, with consequence the smearing of the real
physics in this complicated system. As the present results reveal, there are
two families of samples. The first family concerns samples prepared in
atmosphere ($P({\rm O}_2)=0.2$ Atm) which are all ferromagnetic with Curie
temperature rising with $x$. The second family concerns samples, where a post
annealing in nearly zero oxygen partial pressure is applied. These samples show
a canted antiferromagnetic structure for $0\leq x \leq 0.1$ below $T_N$, while
for $0.125\leq x <0.23$ an unconventional ferromagnetic insulated phase is
present below $T_c$. The most important difference between nonstoichiometric
and stoichiometric samples concerning the magnetic behavior, is the anisotropy
in the exchange interactions, in the stoichiometric samples putting forward the
idea that a new orbital ordered phase is responsible for the ferromagnetic
insulating regime in the La$_{1-x}$Ca$_x$MnO$_3$ compound.

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The categories of this paper are: supr-con
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The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: math
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: cs
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph