Oxygen exchange and phase stability of Y0.8Ca0.2BaCo4-xMxO7+δ (M = Fe, Ga, Al)

Using the sol-gel method, the complex oxides Y0.8Ca0.2BaCo4-xMxO7, where M = Fe, Ga, and Al, with swedenborgite-type structure, were synthesized. The slight replacement of Y by Ca is shown to facilitate doping at cobalt sites. The introduction of iron in place of cobalt is accompanied by a shift in the low-temperature oxygen exchange reaction to higher temperatures. The codoped oxides Y0.8Ca0.2BaCo3.8M0.2O7 demonstrate phase stability at heating in air up to 1000 degrees C.

Automated summary

By using the sol-gel method, complex oxides Y0.8Ca0.2BaCo4-xMxO7 with a swedenborgite-type structure were successfully synthesized. The replacement of Y by Ca facilitates doping at cobalt sites. The introduction of iron instead of cobalt leads to a higher temperature for the low-temperature oxygen exchange reaction. The codoped oxides Y0.8Ca0.2BaCo3.8M0.2O7 show phase stability when heated in air up to 1000 degrees C.