Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Improved Thermoelectric Properties in (1-x)LaCoO3/(x)La0.7Sr0.3CoO3
  Composite   A high Seebeck coefficient (S), large electrical conductivity ({\sigma}), and
reduced thermal conductivity ({\kappa}) are required to achieve a high
figure-of-merit (zT) in an ideal thermoelectric (TE) system, which is
challenging in a single system due to the interdependence of TE parameters.
Composite approach is promising to manipulate the TE parameters. In this study,
TE properties of (1-x)LaCoO3/(x)La0.7Sr0.3CoO3 (0.00 \leq x \leq 0.05)
composite is discussed. The structural analysis confirms individual phases in
the composite, which is further supported by electron microscopy analysis. The
x-ray photoelectron analysis indicates that oxygen vacancies (VO) are present
in the parent LaCoO3 system and increase with the addition of La0.7Sr0.3CoO3
(LSCO) in the composite. The increase in VO raises the degenerate states of
cobalt and hence improves S in the composites. Temperature variation in S and
{\sigma} are consistent with the spin-state transition and shows the
correlation between these two parameters. The reduction in {\kappa} and
{\sigma} with the addition of ball-milled La0.7Sr0.3CoO3 in the composite is
attributed to the enhanced phonon-phonon and charge carrier scattering,
respectively. A synergistic effect of enhanced S and reduced \kappa} result in
five times improvement in zT of the composite compared to the parent LaCoO3
system at 800 K. This approach also improves the operating temperature for
LaCoO3 based systems.

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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th
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The categories of this paper are: atom-ph
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The categories of this paper are: cs
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The categories of this paper are: nlin
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The categories of this paper are: astro-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph
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The categories of this paper are: math
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The categories of this paper are: physics
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The categories of this paper are: math-ph