Mixed-conducting perovskite-type SrxBi1-xFeO3_delta oxygen-permeating membranes

SrxBi1-xFeO3-delta (SBF) series mixed conductors were synthesized using sta ndard ceramic method. The properties of such materials were characterized b y XRD, O-2-TPD techniques. Abnormal crystal phenomena were found and explai ned and correlated with the oxygen permeation results. By analysis of the c ritical radius (r(c)), the degree of openness of the lattice (F-v) and the average metal-oxygen bonding energy of the perovskite lattice (ABE), it was proposed that the oxygen permeation flux is determined mainly by the oxyge n diffusion rate in bulk when 1-x less than or equal to 0.5, and by the con centration of oxygen vacancy when 1-x greater than or equal to 0.5. The sta bility of Sr0.5Bi0.5FeO3-delta was also investigated, and the high stabilit y of it was attributed to the stable BO6 octahedra.