from first principles PP-I-1

PP-III-89Oxygen Isotope Exchange of (1–y)La 1–x Sr x MnO 3±δ · yZr 0.82 Y 0.12 O 1.91Porotnikova N.M., Ananyev M.V., Eremin V.A., Pankratov A.A., Kurumchin E.Kh.Institute of High Temperature Electrochemistry UB RAS, Yekaterinburg, Russiaporotnikova@ihte.uran.ruComposite lanthanum-strontium manganites based materials are successfully used as cathodematerials in Solid Oxide Fuel Cells. Unfortunately, the oxygen exchange mechanism has notbeen fully understood. In this study oxygen isotope exchange method with gas phase analysishave been used for the oxygen exchange mechanism investigation atT = 650―850°C and Po 2 = 1―10 Torr for i) La 1–x Sr x MnO 3±δ with different strontium contentand porosity; ii) (1–y)La 0.6 Sr 0.4 MnO 3±δ · yZr 0.82 Y 0.12 O 1.91 with y = 0―1. The method allowsworking with porous materials as opposed to the depth profiling techniques [1, 2].The interphase exchange rate is shown to increase with strontium content inLa 1–x Sr x MnO 3±δ as in the case of La 1–x Sr x CoO 3–δ investigated in [3], see fig. The oxygenexchange processes in (1–y)La 0.6 Sr 0.4 MnO 3±δ · yZr 0.82 Y 0.12 O 1.91 composites take place both onthe individual components of the composite material and on triple-phase boundaries (TPBs),according to a model suggested in this work.Fig. 1. The interphase exchange rate dependences as functions of Sr content forLSM and LSC oxides and YSZ vol. % for LSM―YSZ composite materials.This work is partly supported by the grant for the young scientists of Ural Branch ofRussian Academy of Sciences in 2012.References:[1] E. Armstrong etc. // Journal of the Electrochemical Society. 158(3) (2011) B283-B289.[2] Y. Ji etc. // Solid State Ionics. 176 (2005) 937-943.[3] M. Ananyev. Oxygen Isotope Exchange. 2012. Lambert. ISBN: 978-3-8484-3040-6.246