Hydrazine-nitrate combustion synthesis of BaCeO3 preceramic powders: structure, morphology and thermophysical properties

In the present work, preceramic nanocrystallite barium cerate (BaCeO3) was successfully synthesized using hydrazine-nitrate combustion method. Using carbon-free hydrazine (N2H4) as fuel significantly reduced formation of carbonate by-products. Subsequent annealing products in air atmosphere at temperatures range 500–1000 °С yielded powders based on chemically and phase-pure BaCeO3. Characterization as-received performed by X-ray diffraction, energy-dispersive spectroscopy (EDXS), scanning electron microscopy (SEM), simultaneous thermal analysis (DTA-TGA) adsorption-structural (N2, 77 K). Thermophysical properties sample annealed 1000 were investigated laser flash (LFA) temperature interval °С. As a result comprehensive study, sequence chemical phase transformations that lead to with rhombic structure (Pnma, = 6.2145 Å, b 8.7776 c 6.2337 Å) during processing investigated. It established average size obtained nanocrystals is 38 ± 3 nm they form micron-sized agglomerates specific surface area powder 4.8 m2/g. shown sintered characterized diffusivity values 0.28 0.20 mm2/s conductivity 0.41–0.35 W/mK, depending temperature. These results, given impact porosity (~40%), show very good agreement thermophysical characteristics densely ceramics BaCeO3—a solid oxide electrolyte SOFC. Consequently, proposed method synthesis presents itself promising approach obtaining cells.