Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Identical effects of indirect and direct electron doping of
  superconducting BaFe2As2 thin films   Electron doping of a 122-type iron pnictide BaFe2As2 by substituting the Ba
site with an aliovalent ion (indirect doping), which had been unsuccessful by
conventional solid-state synthesis methods, was achieved by a non-equilibrium
film growth process. The substitution with La was substantiated by a systematic
shrinkage of the c-axis lattice parameter due to the smaller ionic radius of
La3+ than that of Ba2+. A negative Hall coefficient indicated that the majority
carriers were electrons, as is consistent with this aliovalent ion doping. The
La substitution suppressed an antiferromagnetic transition and induced bulk
superconductivity at a maximum onset critical temperature (Tc) of 22.4 K. The
electronic phase diagram for (Ba1-xLax)Fe2As2 was built, which revealed that
the indirect electron doping at the Ba site with La [(Ba1-xLax)Fe2As2] exhibits
almost the same Tc - doping level relation as that of the direct
electron-doping at the Fe site with Co [Ba(Fe1-xCox)2As2]. This finding
clarified that Tc in 122-type compounds is not affected by a crystallographic
doping site, which is in sharp contrast to the 1111-type compounds, REFeAsO (RE
= rare earth). It is tentatively attributed to the differences in their
dimensionality of electronic structures and electron pairing symmetries.

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The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
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The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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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: hep-th
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The categories of this paper are: bayes-an
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol