Stabilization of cubic perovskite structure upon trivalent cation substitution in Co-based mixed conductors (BaxSr1-x)(Co0.9Y0.1)O3-δ

The stabilization of perovskite through trivalent cation substitution is a promising strategy for the development of oxygen permeation membranes. In this study, perovskite stabilization through yttrium substitution in (BaxSr1-x)(Co0.9Y0.1)O3-δ was investigated and compared with that of Al. A perovskite single phase of (BaxSr1-x)(Co0.9Y0.1)O3-δ was attained at a Ba concentration of 1.0 ≥ x ≥ 0.5, which was higher than the range at which the hexagonal polymorph occurred. This differed from (BaxSr1-x)(Co0.9Al0.1)O3-δ in which the perovskite occurred at a lower Ba concentration than the hexagonal polymorph. In addition, (Ba0.9Sr0.1)(Co0.9Y0.1)O3-δ showed good oxygen permeability on a level similar to that of (Ba0.5Sr0.5)(Co0.8Fe0.2)O3-δ.