Synthesis of Ba0.5Sr0.5Co0.8Fe0.2O3-δ perovskite-type membranes

Ba0.5Sr0.5Co0.8Fe0.2O0.3-δ (designed as BSCF) oxides prepared at different shaping and sintering parameters under the same powder synthesis method were examined in terms of micro structure and disk densities. The oxide powders were synthesized using citrate–EDTA complexing method. The synthesized powders were then formed to disk shaped membranes at sintering temperatures of 1000, 1050 and 1150 °C, pressing pressures of 1000, 2000 and 2500 bar and sintering dwell times of 2, 6 and 10 h, as the best values to cover common used ranges of the parameters. X-ray diffraction (XRD) results of all samples prepared at different condition revealed that the basic structure of perovskite was formed. Although the samples prepared at different conditions have nearly the same microstructure, they demonstrated different relative densities, porosities and grain morphologies. The membrane synthesized at highest temperature and pressure showed the highest relative density, vigorous growth of crystals, better fusion of perovskite structure and less pore numbers. The result showed that the best sintering dwell time is about 8-9 and after that time there is no change in membrane characteristics.

Keywords:

Perovskite oxide , Powder synthesis , Microstructure , Membrane density , Ceramic