Synthesis of nanopowders of the aluminum-substituted lanthanum gallate solid electrolyte by mechanochemical route

► Al-substituted lanthanum gallate as solid oxide electrolyte. ► Mechanosynthesis of La1−xSrxGa1−y−zMgyAlzO3−δ (LSGMA) achieved at room temperature. ► Powder reactivity is enhanced by resorting to poorly crystallized Al2O3 precursor. ► Ceramics free from open porosity are obtained by sintering at 1300-1450 °C. ► Al hinders densification and grain growth explained by cooperative cation diffusion.