New Oxide-Ion Conductors Ln2+xTi2-xO7-x/2 (Ln = Dy – Lu; x=0.096)

New oxide-ion conductors Ln2+xTi2-xO7-x/2 (Ln = Dy-Lu, x = 0.096; 35.5 mol. % Ln2O3· 64.5 mol.% TiO2)-LANTIOX with a disordered pyrochlore structure are obtained by coprecipitation with next thermal annealing at 1600°C. Their ionic conductivity in air at 740°C attains 5·10-3 S/cm for Ln2.096Ti1.904O6.952 (Ln= Lu, Yb), 10-3 S/cm for Ln2,096Ti1,904O6,952 (Ln=Tm, Er, Ho) and 10- 4S/cm for Dy2,096Ti1,904O6,952 due to the presence of defects in both the cation and anion sublattices. The materials contain ~4.8-10.6% LnTi anti-site defects. Ln2.096Ti1.904O6.952 ceramics are shown to be stable in the temperature range of 1400 to 1700°C. 1400°C-samples Ln2+xTi2-xO7-x/2 have lower ionic conductivity then 1600°C and 1690°C samples.