The effect of phase composition on the transport properties of composites La0.8Sr0.2Fe0.7Ni0.3O3 − δ-Ce0.9Gd0.1O1.95

Full conductivity, diffusion and oxygen exchange processes in composites (100 − x)La0.8Sr0.2Fe0.7Ni0.3O3 − δ−xCe0.9Gd0.1O1.95 (x is the volume fraction, 0 ≤ x ≤ 71.1%) at 700°C over the oxygen partial pressure range from 0.2 to 3 × 10−3 atm are studied by the electrical conductivity relaxation method. The composites’ conductivity was shown to decrease monotonically with the increasing of Ce0.9Gd0.1O1.95 fraction, while the oxygen chemical diffusion coefficient increased. The oxygen exchange constant is higher for the composites than for the individual phases of La0.8Sr0.2Fe0.7Ni0.3O3 − δ and Ce0.9Gd0.1O1.95. Possible reason of the dependence of the parameters Dchem and kchem on the temperature, oxygen pressure, and the composite composition is the effect of the interface on the oxygen transfer processes. Most effective oxygen transfer occurs in the composites whose composition approaches La0.8Sr0.2Fe0.7Ni0.3O3 − δ-Ce0.9Gd0.1O1.95 (x = 71%).