Formation of oxygen deficient BaPbO3‐x by oxalate decomposition

BaPbO₃ is assumed to be oxygen deficient but the exact determination has never been reported. The aim of this study is to investigate the correlation between synthetic conditions and the resulting oxygen deficiency of BaPbO_3‐x. The formation of BaPbO_3‐x by decomposition of barium‐ and lead oxalate up to 850 °C is significantly faster compared to conventional high temperature solid state reactions of oxide compounds. The discrete reaction steps were studied by simultaneous thermal analysis and X‐ray powder diffraction. The oxygen content was determined by temperature‐programmed reduction analysis. It is shown that the formation process is very sensitive to the chosen starting materials leading to different oxygen deficits caused by partial oxidation from Pb²⁺ to Pb⁴⁺. The resulting perovskites show chemical compositions of BaPbO_2.74 and BaPbO_2.82. The varying oxygen deficits should have an effect on structural properties. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)