Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Synthesis and Characterization of Excess Magnesium MgB2 Superconductor
  under Inert Carbon Environment   The structural, transport and magnetic properties of MgB2 superconductor
heavily blended with Mg is studied. The samples are synthesized with a new
approach in both, pressed carbon environment and in flowing argon. The excess
magnesium used is observed to play dual role: one being the prevention of Mg
losses during the synthesis process and hence maintaining the stoichiometry of
MgB2 phase, and second being the formation of Mg milieu probably all around the
MgB2 grains to give a ductile and dense structure. Excess Mg also improves the
grain connectivity by going in to the pores and there by minimizing the
insulating junctions.

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The categories of this paper are: acc-phys
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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: eess
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The categories of this paper are: dg-ga
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: q-alg
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The categories of this paper are: gr-qc
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The categories of this paper are: math
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The categories of this paper are: physics