Structural and Electric Properties of Lanthanide Doped Oxybritholites Materials

Oxyapatites are very attractive substances thanks to their high ionic conductivity. These materials could be used in place of yttrium-stabilized zirconia (YSZ), enabling electrical conduction in solid fuel cells at temperatures below 1000 °C. In this paper, a series of Sr10-xLax(PO4)6-x(SiO4)xO with x = 0, 2, 4 and 6 were successfully synthesized using a mechanochemical synthesis method. The resulting powders were then sintered at 1200 °C to improve their crystallinity. The obtained materials were well studied and their characterization revealed that a single-phase apatite was produced and that after calcination, the preference of La³⁺ ions for Me (1) sites shifted to Me (2) sites. The ionic conductivity of raw and calcined materials was studied over a temperature range from 450 to 800 °C. The results showed that the highest value, for apatite, was 1.5%. The results showed that the highest value, 4.179 × 10^–5 S.cm⁻¹, was reached with x = 2 at 800 °C.