Abstract
Preparation of porous substrates (discs) of La0.6Sr0.4CoO3 (LSCO) was investigated as a part of the study on an oxygen semipermeable device based on mixed conductive perovskite-type oxides. Of the several methods attempted, sintering of compacts of an LSCO powder-methylcellulose (MC) mixture and an LSCO-carbon fiber (CF) mixture gave discs with irregular macro-pores which tended to grow parallel to the disc surface or with straight penetrating channels with a uniform diameter, respectively. However, none of them exhibited sufficiently large (physical) air permeability. On the other hand, sintering of a compact of LSCO powder was far more effective if an adequate starting powder was chosen. Thus, when the LSCO powder calcined at 1400°C (LSCO (1400)) with the particle size larger than 10μm was used, the disc sintered at 1400°C showed high air permeability through penetrating channels consisting of a network of intergranular pores. Furthermore, when LSCO (1400) powder was sieved to 44-74μm, the sintered disc had uniform-sized open pores with a diameter of 20 to 30μm, which provided porous structure resistant to heat treatment and high permeability of air. The disc appeared to be suitable as a porous support on which thin membrane of oxygen semipermeable perovskite-type oxides was formed.
