Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconducting MgB(2) films via precursor post-processing approach   Superconducting MgB(2) films with Tc = 38.6 K were prepared using a
precursor-deposition, ex-situ post-processing approach. Precursor films of
boron, ~0.5 micrometer thick, were deposited onto Al(2)O(3) (102) substrates by
e-beam evaporation; a post-anneal at 890 deg C in the presence of bulk MgB(2)
and Mg metal produced highly crystalline MgB(2) films. X-ray diffraction
indicated that the films exhibit some degree of c-axis alignment, but are
randomly oriented in-plane. Transport current measurements of the
superconducting properties show high values of the critical current density and
yield an irreversibility line that exceeds that determined by magnetic
measurements on bulk polycrystalline materials.

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The categories of this paper are: nucl-th
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The categories of this paper are: adap-org
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The categories of this paper are: eess
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: stat
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg