Electrical conductivity of oxygen-deficient perovskite solid-solution system (Ba, La) (In, Ga) O3-delta

Electrical conductivity of the perovskite-type solid-solution system (Ba1-x Lax)(In(1-x)Gax)O3-delta was investigated from a viewpoint of crystal chemi stry. XRD showed that the brownmillerite-type orthorhombic phase (x = 0.0) gradually approached to cubic phase with increase in x, resulting in the cu bic perovskite phase at x greater than or equal to 0.15. A sharp transition temperature (T-d) (930 degrees C) of the electrical conductivity observed for x = 0.0 shifted to lower temperature with increase in x, at the same ti me, the electrical conductivity above the T-d decreased. The shift of T-d w as explained by disordering of oxygen vacancy. On the other hand, it was fo und that the electrical conductivity was strongly affected by the unit cell lattice volume rather than oxygen vacancy.