Structural, microstructural and electrical characterization of BaSnO3 and Ba0.90Y0.10SnO3 synthesized by solution combustion method

Powder of perovskite oxides BaSnO3 and Ba0.90Y0.10SnO3 have been synthesized by solution combustion method. Rietveld profile analysis shows that the phases crystallize with cubic unit cell in the space group pm3m. Further purity of the synthesized powders was checked by Fourier transform of infrared (FTIR) spectroscopy. The average grain size of the sintered samples was obtained using Scaiming electron microscopy (SEM) and found to be 4.9 and 2.8 mu m for BaSnO3 and Ba0.90Y0.10SnO3, respectively. The AC conductivity (sigma(ac)) of synthesized samples was measured in the frequency range froin 24Hz-1MIlz and temperature range 100- 600 degrees C. Conductivity spectra of both the samples followed universal Johnscher's power law at different temperatures. The value of bulk or dc conductivity (sigma(dc)) at different temperatures has been extracted by fitting the dolmscher's power law to AC conductivity spectra. The activation energy for sigma(dc) has been obtained from the least square linear fit of data points and found to be 0.53 eV and 0.43 eV, respectively for BaSnO3 and Ba0.90Y0.10SnO3. Based on the value of activation energy it is proposed that conduction in these samples is govern via hopping of (OW. The value of conductivity at temperature 550 degrees C of Ba0.90Y0.10SnO3 is 0.00406 S-cm(-1) higher than BaSnO3 (0.00173 S-cm(-1)) at the same temperature.