Lanthanum gallate with partial substitution on La and Ga sites (La1-xSrxGa1-yMgyO3-) has perovskite structure and high oxide-ion conductivity. Other properties of this ceramic material comprise a relatively wide electrolytic domain and low electron conductivity. Doped lanthanum gallate is a potential solid electrolyte for intermediate-temperature solid oxide fuel cells due to its high ionic conductivity and stability in a wide range of oxygen partial pressure. In this work, the composition

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... 9Sr0.1Ga0.8Mg0.2O3-was prepared by the conventional method of mixing of the starting oxides followed by different processing routes and by the cation complexation method. The ceramic specimens were consolidated by conventional sintering and by fast firing. All specimens prepared by solid state reaction show the characteristic orthorhombic phase of lanthanum gallate and SrLaGaO4, La4Ga2O9 and SrLaGa3O7 secondary phases, independent on the method of sintering. Energy dispersive X-ray spectroscopy coupled to scanning electron microscopy evidenced that all prepared specimens contain MgO grains precipitated along the grain boundaries. High relative densities were obtained for specimens prepared by solid state reaction and consolidated by conventional sintering at 1450 °C/4 h. All specimens exhibit micron sized grains independent on the sintering method. The highest values of relative density and ionic conductivity were obtained for specimens calcined at 1250°C.