Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Physical properties in hole-doped SrFe$_{2-x}$Cu$_x$As$_2$ single
  crystals   We report the structural, magnetic and electronic transport properties of
SrFe$_{2-x}$Cu$_x$As$_2$ single crystals grown by self-flux technique.
SrCu$_2$As$_2$ and SrFe$_2$As$_2$ both crystallize in ThCr$_2$Si$_2$-type
(122-type) structure at room temperature, but exhibit distinct magnetic and
electronic transport properties. The x-ray photoelectron spectroscopy(XPS)
Cu-2p core line position, resistivity, susceptibility and positive Hall
coefficient indicate that SrCu$_2$As$_2$ is an sp-band metal with Cu in the
3d$^{10}$ electronic configuration corresponding to the valence state
Cu$^{1+}$. The almost unchanged Cu-2p core line position in
SrFe$_{2-x}$Cu$_x$As$_2$ compared with SrCu$_2$As$_2$ indicates that partial Cu
substitutions for Fe in SrFe$_2$As$_2$ may result in hole doping rather than
the expected electron doping. No superconductivity is induced by Cu
substitution on Fe sites, even though the structural/spin density wave(SDW)
transition is gradually suppressed with increasing Cu doping.

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The categories of this paper are: cs
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The categories of this paper are: adap-org
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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: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: math
34
The categories of this paper are: chem-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: econ
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The categories of this paper are: gr-qc
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys
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The categories of this paper are: physics
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The categories of this paper are: mtrl-th
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The categories of this paper are: eess