Реферат: Doped La2-xRxMo2-yWyO9 (LAMOX) (R= Bi, Gd, Pr, Sm, Nd; x=0-0.5, W=0.5-1) were synthesized via polymerized precursors method or mechanochemical activation. The structural properties of doped LAMOX were studied by thermal analysis, XRD, SEM, IR and Raman spectroscopy. Transport properties were characterized using impedance spectroscopy and isotope temperature–programmed exchange with C18O2 including SSITKA. It has been revealed that doping prevents phase transition from a cubic form of high conductivity to a monoclinic phase of low conductivity at about 580 °C. For all substituted cations in Laposition, well-crystalline cubic β-phase stable at low temperatures is formed from polymerized precursors at 700°C calcination except Bi. Single phase of cubic W-doped LAMOX is formed after calcination of MA products at 700-900°C depending on W concentration. High dispersion of doped LAMOX powders obtained via low-temperature synthesis allows the production of ceramics with the density of 92-95% after annealing at 950°C. If the total conductivity of La2Mo2O9 shows a sharp decrease at around 570 °C due to phase transition, for all doped LAMOX conductivity changes continuously with temperature rising due to stabilization of cubic phase at low temperature. In the range of 300-480oC, it can be satisfactorily fitted by a conventional Arrhenius-type law with the activation energy (Ea) 1.2-1.5 eV. The conductivity deviation from linearity observed at temperatures higher than 450 oC evidences the transition of conduction mechanism toward an empirical Vogel-Tammann-Fulcher (VTF) regime with Ea=0.045 eV. Comparison of the oxygen selfdiffusion coefficients (D0) obtained from the results of SSITKA and conductivity measurements (at 600 K ~3*10-13 cm2/s and 3*10-12 cm2/s, correspondingly) shows, in the first approximation, a reasonable agreement. The lower D0 of SSITKA could be due to incorporation of carbonate groups at low temperatures into the surface layers of LAMOX thus decreasing oxygen mobility. Support by EC 7th Framework Program within TheBarCode Project is gratefully acknowledged

Библиографическая ссылка: Pavlova S.N. , Bespalko Y.N. , Sadykov V.A. , Pelipenko V.V. , Eremeev N.F. , Krieger T.A. , Chesalov Y.A. , Sadovskaya E.M. , Ulikhin A.S. , Uvarov N.F. , Smirnova A.L.
Structural and Transport Properties of Doped LAMOX - Electrolytes for IT SOFC
20th International Conference on Solid State Ionics (SSI-20) 14-19 Jun 2015