Structural studies of Sr- and Mg-doped LaGaO3

A series of La1−xSrxGa1−yMgyO3−δ (LSGM) solid solution were prepared by solid state synthesis and characterized by X-ray phase analysis at room temperature. A systematic change of crystal structure with the increase in A- and B-site dopant contents was observed. At a total dopant concentration of 25 at%, the crystal structure was found to be orthorhombic whereas at a total dopant concentration of 35 at% keeping at least one component at 20 at%, the structure was observed to be cubic. Mixed structures of orthorhombic and rhombohedral were also found at intermediate dopant concentrations. A structural phase diagram is proposed based on the findings and co-related with the oxygen ionic conductivity.