Processing and Application of Ceramics 2017 Volume 11, Issue 3, Pages: 177-184
https://doi.org/10.2298/PAC1703177K
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Structural and optical characterizations of BaSnO3 nanopowder synthesized by aqueous sol-gel method
Kumar Upendra (Indian Institute of Technology (Banaras Hindu University), Department of Physics, Varanasi, U.P., India)
Ansaree Jawed (Indian Institute of Technology (Banaras Hindu University), Department of Physics, Varanasi, U.P., India)
Upadhyay Shail (Indian Institute of Technology (Banaras Hindu University), Department of Physics, Varanasi, U.P., India)
Precursor gel for preparation of nanocrystalline BaSnO3 powder was
synthesised by aqueous sol-gel method using Ba(OH)2 • 8H2O and Na2SnO3 •
3H2O as raw materials. Thermogravimetric and differential scanning
calorimetric analyses of the raw materials, precursor gel and a mechanical
mixture of raw materials were carried out to understand the mechanisms
involved in the formation of the single phase BaSnO3. Based on the thermal
analysis, the precursor gel was calcined at 400, 800 and 1400°C for 4 h to
obtain pure phase BaSnO3 powder. X-ray diffraction pattern of the powder
calcined at 1400°C was refined for atomic coordinate, lattice parameter (a
= 4.1117(2)Å) and occupancies using Rietveld refinement analysis. The
average crystallite size calculated from the Scherrer formula is ~35 nm.
Transmission electron micrograph of the powders confirmed that particle
sizes are in range of 20-40 nm. The phase purity of the powder calcined at
1400°C was further examined by Fourier transform infrared spectroscopy.
Optical properties of the BaSnO3 powder were studied by UV-visible
absorption and photoluminescence (PL) spectra. The band gap energy (3.09 eV)
obtained from the Tauc plot confirmed the semiconductor nature of the
powder. The CIE coordinate corresponding to PL spectrum exhibited an intense
emission in the visible region.
Keywords: BaSnO3, sol-gel, structural characterization, optical properties