Synthesis and characterization of porous la _1-xSr _xCo _1-yFe _yO _3-δ membranes fabricated using by electrostatic spray deposition

In this research, the electrostatic spray deposition (ESD) technique was applied for the deposition of a thin La _0.8SrO _0.2Co _0.2Fe _0.8O _3-δ (LSCF) membrane on a porous a-alumina substrate. The spray mode from the nozzle varied from the dripping mode to the cone-jet mode with increasing applied high voltage between the nozzle and the substrate. The morphology of the thin LSCF membrane was strongly affected by the substrate temperature and a crack-free membrane was obtained at an optimum substrate temperature of 340°C, followed by annealing at 1000°C under an O ₂ atmosphere. The ESD, drying and annealing were repeated to get a rigid, crack-free membrane structure. After three coatings, the LSCF layer was about 3 μm in thickness. These thin films were characterized using SEM, DTA-TGA, XRD and EDX in addition to helium permeation tests, which showed that thin LSCF membranes were pin-hole (or crack) free.