Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Site-Selective Oxygen Vacancy Formation Derived from the Characteristic
  Crystal Structures of in Sn-Nb complex Oxides   Divalent tin oxides have attracted considerable attention as novel p-type
oxide semiconductors, which are essential for realizing future oxide electronic
devices. Recently, p-type Sn2Nb2O7 and SnNb2O6 were developed; however,
enhanced hole mobility by reducing defect concentrations is required for
practical use. In this work, we investigate the correlation between the
formation of oxygen vacancy which may reduce the hole-generation efficiency and
hole mobility, and the crystal structure in Sn-Nb complex oxides. Extended
X-ray absorption fine structure spectroscopy and Rietveld analysis of x-ray
diffraction revealed the preferential formation of oxygen vacancy at the O site
bonded to the Sn ions in both the tin niobates. Moreover, a large amount of
oxygen vacancy around the Sn ions were found in the p-type Sn2Nb2O7, thereby
indicating the effect of oxygen vacancy to the low hole-generation efficiency.
The dependence of the formation of oxygen vacancy on the crystal structure can
be elucidated from the Sn-O bond strength that is evaluated based on the bond
valence sum and Debye temperature. The differences in the bond strengths of the
two Sn-Nb complex oxides are correlated through the steric hindrance of Sn2+
with asymmetric electron density distribution. This suggests the importance of
the material design with a focus on the local structure around the Sn ions to
prevent the formation of oxygen vacancy in p-type Sn2+ oxides.

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The categories of this paper are: hep-th
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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: cs
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The categories of this paper are: math
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex
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The categories of this paper are: supr-con
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The categories of this paper are: chem-ph
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The categories of this paper are: physics
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The categories of this paper are: bayes-an