Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Band gap tuning and orbital mediated electron phonon coupling in
  $HoFe_{1-x}Cr_xO_3$   We report on the evidenced orbital mediated electron phonon coupling and band
gap tuning in HoFe1-xCrxO3 compounds. From the room temperature Raman
scattering, it is apparent that the electron-phonon coupling is sensitive to
the presence of both the Fe and Cr at the B-site. Essentially, an Ag like local
oxygen breathing mode is activated due to the charge transfer between Fe3+ -
Cr3+ at around 670 cm-1, this observation is explained on the basis of
Franck-Condon (FC) mechanism. Optical absorption studies infer that there
exists a direct band gap in the HoFe1-xCrxO3 compounds. Decrease in band gap
until x = 0.5 is ascribed to the broadening of the oxygen p orbitals as a
result of the induced spin disorder due to Fe3+ and Cr3+ at B site. In
contrast, the increase in band gap above x = 0.5 is explained on the basis of
the reduction in the available unoccupied d - orbitals of Fe3+ at the
conduction band. We believe that above results would be helpful for the
development of the optoelectronic devices based on the ortho-ferrites.

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The categories of this paper are: cmp-lg
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The categories of this paper are: q-fin
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The categories of this paper are: eess
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
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The categories of this paper are: stat
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
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The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: q-alg