Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic anisotropy, magnetic field-temperature phase diagram and
  their dependence on resistivity in c-axis oriented MgB2 thin films   An important predicted, but so far uncharacterized, property of the new
superconductor MgB2 is electronic anisotropy arising from its layered crystal
structure. Here we report on three c-axis oriented thin films, showing that the
upper critical field anisotropy ratio Hc2par/Hc2perp is 1.8 to 2.0, the ratio
increasing with higher resistivity. Measurements of the magnetic
field-temperature phase diagram show that flux pinning disappears at H* ~
0.8Hc2perp(T) in untextured samples. Hc2par(0) is strongly enhanced by alloying
to 39 T for the highest resistivity film, more than twice that seen in bulk
samples.

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The categories of this paper are: stat
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: solv-int
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The categories of this paper are: econ
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The categories of this paper are: quant-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: gr-qc
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The categories of this paper are: eess
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The categories of this paper are: chem-ph