Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Irreversibility line and low-field grain-boundary pinning in
  electron-doped superconducting thin films   AC magnetic susceptibilities of electron-doped Pr_{1.85}Ce_{0.15}CuO_4 (PCCO)
and Sm_{1.85}Ce_{0.15}CuO_4 (SCCO) granular thin films have been measured as a
function of temperature and magnetic-field strength. Depending on the level of
homogeneity of our films, two different types of the irreversibility line (IL)
defined as the intergrain-loss peak temperature in the imaginary part of
susceptibility have been found. The obtained results are described via the
critical-state model taking into account the low-field grain-boundary pinning.
The extracted pinning-force densities in more granular SCCO films turn out to
be four times larger than their counterparts in less granular PCCO films.

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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
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The categories of this paper are: funct-an
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The categories of this paper are: stat
8
The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn