Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Angular Dependence of X-ray Absorption Spectrum for Field-aligned
  Fe-based Superconductors   Anisotropic Fe K-edge and As K-edge X-ray absorption near edge spectrum
(XANES) measurements on superconducting (T_c = 52 K)
(Sm_{0.95}La_{0.05})FeAs(O_{0.85}F_{0.15}) field-aligned microcrystalline
powder are presented. The angular dependence of Fe pre-edge peak (dipole
transition of Fe-1s electrons to Fe-3d/As-4p hybrid bands) relative to the
tetragonal ab-plane of aligned powder indicates larger density of state (DOS)
along the c-axis, and is consistent with the LDA band structure calculation.
The anisotropic Fe K-edge spectra exhibit a chemical shift to lower energy
compared to FeO which are closely related to the itinerant character of
Fe^{2+}-3d^6 orbitals. The anisotropic As K-edge spectra are more or less the
mirror images of Fe K-edge due to the symmetrical Fe-As hybridiztion in the
FeAs layer. Angular dependence of As main peak (dipole transition of As-1s
electrons to higher energy hybrid bands) was observed suggesting character of
As-4d e_g orbitals.

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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: q-fin
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The categories of this paper are: quant-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
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The categories of this paper are: solv-int
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The categories of this paper are: econ
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The categories of this paper are: mtrl-th
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The categories of this paper are: math
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The categories of this paper are: astro-ph
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The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph