REVERSIBLE CYCLING OF THE OXYGEN-CONTENT IN CO-SUBSTITUTED YBAFECUO5+DELTA

The reversible cycling of the oxygen content in layered Go-substituted perovskites of type YBaFeCuO5+delta was investigated applying thermoa nalytical methods. For the system YBaCoCu-xFexO5+delta an increasing a mount of oxygen incorporation into the oxygen deficient lattice was fo und by thermogravimetry for an increasing iron content of x=0.4 to 0.8 . With a cycle of subsequent heating and cooling the reversible incorp oration of oxygen on account of redox active cations with mixed valenc ies could be demonstrated. The combination of several cycles under dif ferent gas atmospheres confirmed the reversibility of the oxidation pr ocesses suggesting the application for catalytical processes.