Transport properties of La0.4Sr0.6CoO3-δ

La0.4Sr0.6CoO3-delta was prepared by the glycine nitrate process and characterized in respect of purity and phase composition by powder X-ray diffraction and analytical transmission electron microscopy. The oxygen-nonstoichiometry, as a function of oxygen partial pressure (10(-4) bar < p(O2) < 10(-2) bar) and temperature (300 degreesC < T < 900 degreesC) as well as the chemical diffusion coefficient (725 degreesC and 825 degreesC), were determined by means of oxygen exchange measurements. Electronic conductivity as measured with the van der Pauw-technique is given as a function of temperature (between 300 degreesC and 900 degreesC) and oxygen partial pressure. With the obtained values for the oxygen-nonstoichiometry of La0.4Sr0.6CoO3-delta, it is possible to take into account the change of the oxygen content of the sample with temperature and to calculate isostoichiometric (delta = constant) electronic conductivities. Additionally, chemical diffusion and surface exchange coefficients could be obtained from oxygen exchange measurements using simplified and exact fitting procedures. (C) 2001 Elsevier Science B.V. All rights reserved.