The presented work comprises six original research articles on the solid state chemistry of selected cubic perovskite-type oxides. Cobalt containing mixed conducting perovskite-type materials like (Ba0. 5Sr0. 5)(Co0. 8Fe0. 2)O3 (BSCF) show exceptionally high oxygen fluxes. But serious long-term stability problems in the intermediate temperature (IT) range of 500-800 °C and a high coefficient of thermal expansion due to the flexible redox behavior of cobalt are reported. Thus, a great effort is put into the development of cobalt-free perovskite-type oxides. This book presents results concerning two novel promising cobalt-free perovskite materials containing iron, zinc or aluminum with the stoichiometries (Ba0. 5Sr0. 5)(Fe0. 8Zn0. 2)O3 (BSFZ) and (Ba0. 5Sr0. 5)(Fe1-xAlx)O3 (BSFA). For an accurate atomic level understanding of the solid state chemistry integrative investigations, like oxygen permeation or X-ray diffraction, were combined throughout the whole book with microscopic studies derived from analytical electron microscopy.
