TITLE:
Synthesis, Characterization, Optical and Transport Properties of BaSnO3 Synthesized by Wet Chemical Route
AUTHORS:
Rakesh Kurre, Sharmila Bajpai, Parmendra Kumar Bajpai
KEYWORDS:
X-Ray Diffraction, Raman Spectra, Variable Range Hopping, Phonons
JOURNAL NAME:
Materials Sciences and Applications,
Vol.9 No.1,
January
12,
2018
ABSTRACT: Alkaline
earth stannates have renewed attention as potential materials for gas sensing,
transparent conducting oxides and ceramic capacitor applications. A noble wet
chemical route is chosen to synthesize BaSnO3 powders having micron
size grains. Problems related to uneven grains and poor densification in
conventional solid state route have been
overcome in the present method. X-ray diffraction data confirms the single
phase formation without any secondary phase having cubic perovskite structure
(S.G. Pm-3m). The estimated lattice parameter is ≈4.11933Å and percentage density is ≈90%. The microstructure
probed by scanning electron micrograph reveals almost homogeneously distributed
particles having random shape with some porosity. Phonon modes in FT-IR and
Raman spectra confirm the local symmetry distortion. The DC conductivity at
200°C approaches almost 2 × 10-2 (Ω-cm)-1,
which is almost of the same order as that observed in perovskite based
electronic conductors. DC and a.c. electrical conductivity of the material
follow Mott’s variable range hopping at low temperature and Arrhenius type
thermally activated process at elevated temperatures. Evidence of small polar on
formation is also verified. Optical band gap estimated from absorption data is
≈2.94 very close to the reported value. Composition prepared through the noble
wet chemical route has high electrical conduction and suitable for gas sensing
applications.