Iodometric titration analysis for BaCe0.6Zr0.2Y0.2-xFexO3-δ (x = 0.02, 0.05, 0.1)

The determination of oxygen nonstoichiometry in the series of BaCe0.6Zr0.2Y0.2-xFexO3-δ (x = 0.02, 0.05, 0.1) compounds was carried out using the iodometric titration method. The procedure steps were as following: (1) purging the flask with argon for 20 minutes to remove air, after which the powdered material (15-20 mg), along with KI (0.2 g), was dissolved in 2 M hydrochloric acid; (2) 0.01 M Na2S2O3 was added to the solution; (3) 1 wt.% starch water solution was incorporated towards the end of the titration. The amount of I3- ions released was evaluated based on the volume of sodium thiosulfate used in the titration, which allowed for the determination of oxygen nonstoichiometry.