Phase relationship of barium and magnesium doped LaGaO3 perovskite oxides

The formation of phases in Ba2+ and Mg2+ ions doped perovskite system and the relationship among the formed phases were investigated by the powder X-ray diffraction method. Ba2+ ion was hardly dissolved into La site in the La1-xBaxGaO3-delta system so that BaLaGa3O7 and BaLaGaO4 were formed as the secondary phases. In the LaGa1-yMgyO3-delta system, the LaGaO3 single phase was produced in the composition region y less than or equal to 0.25 and La4Ga2O9 was produced at the composition y = 0.3 as the secondary phase. In the La1-xBaxGa1-yMgyO3-delta system, Ba2+ ion could be dissolved into La site of the LaGaO3 structure together with dissolution of Some Mcr ion into Ga site. A new compound La3GaMgO7 of a tetragonal structure was found in the compositions doped by large amount of Mg2+ ion. (C) 2002 Elsevier Science B.V. All rights reserved.