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Doped La2-xRxMo2-yWyO9 (R= Bi, Gd, Pr, Sm, Nd; x=0-0.5, y=0.5-1) were synthesized via polymerized precursors method or high power mechanical milling (MM). The study of doped LAMOX genesis and structural properties using thermal analysis, XRD, SEM, IR and Raman spectroscopy has revealed that for all cations but Bi substituting La-position, the pure cubic β-phase is formed from polymerized precursors after calcination at 700°C. W-doped LAMOX have been obtained via low temperature calcination of MM products depending on W concentration. Due to a high dispersion of powders, high density pellets of doped LAMOX ceramics have been already obtained after annealing at 950°C. Their electrical conductivity measured by impedance spectroscopy depends on the doping cation nature being sufficiently high (up to 5.6∙10-3 S/cm at 630 ºC) at temperature below 650°C.

The present paper is devoted to optimization of composites (100-z) wt.% La1-ySryFe0.7Ni0.3O3-δ - z wt.% Ce0.9Gd0.1O2-δ (GDC) and study of the effect of Sr doping of perovskite and GDC content in the sample on structural and transport features of the composites. The results on the research of structural and microstructural features of the composites and their transport properties by using XRD, HRTEM, EDX analysis, electrical conductivity measurements, oxygen isotope heteroexchange and conductivity as well as weight relaxation techniques are presented and discussed.

Structural features of Fe- and Al-doped apatite-type lanthanum silicates with different stoichiometry have been studied by using XRD, XPS, IR, UV-Vis, EXAFS, Mossbauer, 29Si and 27Al MAS NMR spectroscopy. The transport properties of the samples were also characterized by using impedance spectroscopy and oxygen isotope heteroexchange.

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