Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phonon Anomalies, Orbital-Ordering and Electronic Raman Scattering in
  iron-pnictide Ca(Fe0.97Co0.03)2As2: Temperature-dependent Raman Study   We report inelastic light scattering studies on Ca(Fe0.97Co0.03)2As2 in a
wide spectral range of 120-5200 cm-1 from 5K to 300K, covering the tetragonal
to orthorhombic structural transition as well as magnetic transition at Tsm ~
160K. The mode frequencies of two first-order Raman modes B1g and Eg, both
involving displacement of Fe atoms, show sharp increase below Tsm.
Concomitantly, the linewidths of all the first-order Raman modes show anomalous
broadening below Tsm, attributed to strong spin-phonon coupling. The high
frequency modes observed between 400-1200 cm-1 are attributed to the electronic
Raman scattering involving the crystal field levels of d-orbitals of Fe2+. The
splitting between xz and yz d-orbital levels is shown to be ~ 25 meV which
increases as temperature decreases below Tsm. A broad Raman band observed at ~
3200 cm-1 is assigned to two-magnon excitation of the itinerant Fe 3d
antiferromagnet.

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The categories of this paper are: astro-ph
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The categories of this paper are: math
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: eess
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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: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci