Effect of the firing temperatures on the phase formation, microstructure and electrical properties of BaTi0.91 Sn0.09O3 ceramics synthesized via the solid state combustion method

BaTi0.91Sn0.09O3 (BTS) ceramics were synthesized by the solid state combustion method with glycine as the reducting agent and metal nitrates as the oxidants. The calcination and sintering temperatures were in the range of 1200 degrees C-1300 degrees C and 1300 degrees C-1450 degrees C, respectively, for 2 h. Pure perovskite powders were obtained from the samples calcined at >= 1275 degrees C for 2 h. The crystal size calculated by Scherrer equation was in the range of 22-30 nm. XRD results of the sintered ceramics showed the coexistence of the tetragonal (T) and orthorhombic (O) phases in all samples, and were confirmed by Rietveld refinement. The grain sizes increased from 9.04 to 29.83 mu m when the sintering temperatures increased from 1300 degrees C-1450 degrees C for 2 h. The highest density (5.95 gcm(-3)), large piezoelectric strain (d(33)* = 830 pm/V) and best dielectric constant (epsilon(r) = 14841) were obtained from the sample sintered at 1350 degrees C for 2 h. This study clearly demonstrates the potential of the solid state combustion method for producing high density and good dielectric properties in BTS ceramics.