Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical and electronic properties in ferroelectric barium titanate-based
  compounds   The bandgap energy values for the ferroelectric BaTiO3-based solid solutions
with isovalent substitution Ba1-x SrxTiO3, BaZrxTi1-xO3 and BaSnxTi1-xO3 were
determined using diffuse reflectance spectra. While the corresponding unit cell
volume follows Vegard's law in accordance with the different ionic radii of the
ionic substitutions, the bandgap values depict non-linear compositional
dependences for all the solid solutions. The effect is considerably large for
BaZrxTi1-xO3 and BaSnxTi1-xO3 solutions, depicting a bandgap linear
compositional dependence up to x=0.6, for x>0.6 BaZrxTi1-xO3 compounds present
much larger bandgap values than BaSnxTi1-xO3 counterparts. Electronic
properties have been investigated through X-ray photoelectron spectroscopy in
BaSnxTi1-xO3 compounds, indicating that the Sn 3d and Ti 2p core levels shift
against the Ba 3d ones within the whole compositional range with the same
energy trend as that observed for the optical bandgap. Since for Ba1-x SrxTiO3
compounds no major bandgap variation is observed, we conclude that the bandgap
compositional dependences observed for BaSnxTi1-xO3 compounds and BaZrxTi1-xO3
ones are originated from the structural sensitivity of the O, Ti and Sn or Zr
electronic bands involved in the bandgap transition of these compounds. With
this work, we underline the reliability of the bandgap determined from diffuse
reflectance spectrometry experiments, as a means to non-invasively evaluate the
electronic properties of powder materials.

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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
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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: solv-int
0
The categories of this paper are: hep-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
2
The categories of this paper are: math
1
The categories of this paper are: cs
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn