Abstract
LaSrGa3O7 – based oxide-ionic conductors were prepared by a novel solution method as well as a conventional solid-state method. From X-ray diffraction patterns, it was confirmed that La1.5Sr0.5Ga3O7+δ as well as LaSrGa3O7 were successfully prepared as a single phase of the melilite structure by both the synthetic processes. In addition, it was found that the grain sizes were 2～10 µm and a few hundred nm in the sintered samples synthesized by the solid-state and solution methods, respectively. As for these compacts, conductivity measurements were carried out with an AC impedance technique. As a result, it was demonstrated that the electrical conductivity was essentially independent of the synthetic method, even though the sintering temperature in the solution method was much lower than that in the conventional method. From the conductivity measurements under O2 and Ar atmospheres, it was also confirmed that La1.5Sr0.5Ga3O7+δ exhibited predominant oxide-ion conduction regardless of the synthetic method.
