Effect of Co doping on oxygen permeation in Sr3Ti2O7 with Ruddlesden-Popper structure

Effects of transition metal dopant to Ti site in Sr3Ti2-xMxO7 (M = Fe, Ga, Co) on the electrical conductivity and the oxygen permeation property were investigated. Among the examined dopants, it was found that doping Co is the most effective for improving the electrical conductivity and the oxygen permeation rate. With increasing Co amount, electrical conductivity and oxygen permeation rate monotonically increased and the highest oxygen permeation rate is achieved at Sr3Ti0.8Co1.2O7 among the Co doped sample. On this composition, the oxygen permeation rate from air to He is achieved a value of 2.02 cc/min.cm2 at 1273 K.