Structural, microstructural and electrical characterization of BaSnO_3 and Ba_(0.90)Y_(0.10)SnO_3 synthesized by solution combustion method

摘要

Powder of perovskite oxides BaSnO_3 and Ba_(0.90)Y_(0.10)SnO_3 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 Scanning electron microscopy (SEM) and found to be 4.9 and 2.8 1m for BaSnO_3 and Ba_(0.90)Y_(0.10)SnO_3, respectively. The AC conductivity (σ_(ac)) of synthesized samples was measured in the frequency range from 24Hz-1MHz and temperature range 100 - 600°C. Conductivity spectra of both the samples followed universal Johnscher's power law at different temperatures. The value of bulk or dc conductivity (σ_(dc)) at different temperatures has been extracted by fitting the Johnscher's power law to AC conductivity spectra. The activation energy for σ_c 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 BaSnO_3 and Ba_(0.90)Y_(0.10)SnO_3. Based on the value of activation energy it is proposed that conduction in these samples is govern via hopping of (OH)·. The value of conductivity at temperature 550°C of Ba_(0.90)Y_(0.10)SnO_3 is 0.00406 S-cm~(-1) higher than BaSnO_3 (0.00173 S-cm~(-1)) at the same temperature.