Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Structure and Physical properties of New layered oxypnictides
  $Sr_4Sc_2O_6M_2As_2$ (M=Fe and Co)   We have successfully prepared the new layered oxypnictides
$Sr_4Sc_2O_6M_2As_2$ (M=Fe and Co). They adopt the tetragonal structure, being
the same as that of $Sr_4Sc_2O_6Fe_2P_2$. The lattice constants are a=0.4045 nm
and c= 0.5802 nm for M=Fe, and a=0.4045 nm and c=1.5695 nm for M=Co,
respectively. Their transport and magnetic properties have been systematically
studied. The temperature dependence of Hall coefficient and thermoelectric
powder for $Sr_4Sc_2O_6Fe_2As_2$ compound show complicated behavior, similar to
that of iron-based parent compounds LnOFeAs and $BaFe_2As_2$. It suggests that
the $Sr_4Sc_2O_6Fe_2As_2$ could be considered a new parent compound as
iron-based superconductors.

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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-alg
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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: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: ao-sci
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
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The categories of this paper are: astro-ph