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

La0.4Sr0.6CoO3-delta was prepared by the glycine nitrate process and charac terized in respect of purity and phase composition by powder X-ray diffract ion and analytical transmission electron microscopy. The oxygen-nonstoichio metry, 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 che mical diffusion coefficient (725 degreesC and 825 degreesC), were determine d by means of oxygen exchange measurements. Electronic conductivity as meas ured with the van der Pauw-technique is given as a function of temperature (between 300 degreesC and 900 degreesC) and oxygen partial pressure. With t he 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 th e sample with temperature and to calculate isostoichiometric (delta = const ant) electronic conductivities. Additionally, chemical diffusion and surfac e exchange coefficients could be obtained from oxygen exchange measurements using simplified and exact fitting procedures. (C) 2001 Elsevier Science B .V. All rights reserved.