Solution-combustion synthesis of Bi1-xLnxO1.5 (Ln = Y and La-Yb) oxide ion conductors

Cubic fluorite related Bi1-xLnxO1.5 (Ln = Y and La-Yb) phases are synthesized by solution-combustion method using glycine as the fuel. The cubic fluorite phase is stabilized with 25 mole% of rare earth cations. The lattice parameter of cubic phase increases linearly with size of the lanthanide ion. The synthesized powders are nano-metric in size and exhibit excellent compactability and reach 98% densification even on short period of sintering. The oxides with relatively larger cations Nd, Sm, Eu, Pr and Gd with 25 mole % composition transform to rhombohedral structure while others retain cubic upon sintering. All the phases show high oxide-ion conductivity and the values obtained are in good agreement with the reported values. (author)