Co-existence of cubic and orthorhombic phases in Ba-doped LaInO3 and their effect on conductivity

La1−xBaxInO3−δ system was synthesized to understand the phase formation and their relationship with conduction phenomena. Rietveld analysis has been performed to confirm the presence of crystalline phases. At room temperature, the system is a single phase up to x=0.05 with space group Pnma. However, higher concentration of dopant leads to formation of cubic and orthorhombic phases for x=0.1–0.15 samples. Raman spectra further verified Ba-substitution at La-site in lanthanum indate. Ac conductivity has been measured as a function of temperature and Ba content. The highest conductivity observed is ~3 mS cm−1 for x=0.1 sample at 700 °C. The activation energy indicates that the nature of present samples is like oxide ion conductors and is almost invariant with increasing Ba-content. The thermal expansion coefficient (TEC) of present samples is in the order as required for SOFC applications.