Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quenching Dependence on Superconductivity in the Synthesizing Process of
  Single Crystals of Rb$_x$Fe$_{2-y}$Se$_2$   Superconducting single crystals of Rb-intercalated FeSe compounds
Rb$_x$Fe$_{2-y}$Se$_2$ were prepared by using a starting material of Rb$_2$Se
as a Rb source. The superconducting properties and the surface microstructures
were systematically controlled by varying the cooling rate in the quenching
process. The higher cooling rate in the sample provided a higher
superconducting transition temperature with highly connected superconducting
mesh-like surface structure. Extremely slow-cooling process led to the complete
isolation between the superconducting domains.

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The categories of this paper are: econ
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-th
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The categories of this paper are: q-bio
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The categories of this paper are: astro-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: cs
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: physics
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The categories of this paper are: nucl-th
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat