Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Synthesis, structural and transport properties of the hole-doped
  Superconductor Pr_{1-x}Sr_xFeAsO   Superconductivity was achieved in PrFeAsO by partially substituting Pr^{3+}
with Sr^{2+}. The electrical transport properties and structure of this new
superconductor Pr_{1-x}Sr_xFeAsO at different doping levels (x = 0.05$\sim$
0.25) were investigated systematically. It was found that the lattice constants
(a-axis and c-axis) increase monotonously with Sr or hole concentration. The
superconducting transition temperature at about 16.3 K (95% $\rho_n$) was
observed around the doping level of 0.20$\sim$ 0.25. A detailed investigation
was carried out in the sample with doping level of x = 0.25. The domination of
hole-like charge carriers in this material was confirmed by Hall effect
measurements. The magnetoresistance (MR) behavior can be well described by a
simple two-band model. The upper critical field of the sample with T_c = 16.3 K
(x = 0.25) was estimated to be beyond 45 Tesla. Our results suggest that the
hole-doped samples may have higher upper critical fields comparing to the
electron-doped ones, due to the higher quasi-particle density of states at the
Fermi level.

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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: eess
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The categories of this paper are: gr-qc
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The categories of this paper are: physics
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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: adap-org
0
The categories of this paper are: hep-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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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: q-bio