Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Temperature- and magnetic-field-dependent resistivity of MgB2 sintered
  at high temperature and high pressure condition   We report the temperature- and magnetic-field-dependent resistivity of MgB2
sintered at high temperature and high pressure condition. The superconducting
transition width for the resistivity measurement was about 0.4 K, and the
low-field magnetization showed a sharp superconducting transition with a
transition width of about 1 K. The resistivity in the normal state roughly
followed T^2 behavior with smaller residual resistivity ratio (RRR) of 3 over
broad temperature region above 100 K rather than reported T^3 behavior with
larger RRR value of ~ 20 in the samples made at lower pressures. Also, the
resistivity did not change appreciably with the applied magnetic field, which
was different from previous report. These differences were discussed with the
microscopic and structural change due to the high-pressure sintering.

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The categories of this paper are: astro-ph
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The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
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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: q-bio
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The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
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The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th