In this paper to improve the ionic conduction properties, lanthanum silicate apatite La9.33(SiO4)6O2 ceramic, which substituted by V ions at Si-site, were fabricated by the mixed-oxide method. And we investigated the structural and electrical properties of La9.33(Si6-□v□)6O26 specimens with variation of dopants for the application of solid oxide fuel cells. The sintering temperature of La9.33(Si6-□v□)O26 specimens decreased from 1,600℃ to 1,400℃. As results of X-ray diffraction patterns, all La9.33(Si6-□-□)O26 specimens showed the formation of a complete solid solution in a apatite polycrystallin structure. But the specimens doped with more than 1.5mol% showed the second phase, La2 SiO5 and SiO2. The specimen dopants with 1.0 mol% showed the maximum ion conductivity. Ion conducting and activation energy of the La9.33(Si5V1)O26 specimens were about 7.8×10-4 S/cm 1.62 eV at 600℃, respectively.

Citations

• Sr_1.95Fe_1.35Ni_0.15Mo_0.5O_6-δ Perovskite Oxide as Anode Material for Direct Linz-Donawitz Converter Gas Fueled Solid Oxide Fuel Cells
  Han-Bit Park, Ki-Tae Lee
  Journal of Electrical and Electronic Materials.2026; 39(4): 364.     CrossRef

La7.33Bi2 (SiO4)6O2 specimens were fabricated by standard solid-state synthesis route for solid oxide electrolytes. The calcined powders exhibited uniform particles with a mean particle size of about 28μm. The room-temperature structure of La7.33Bi2 (SiO4)6O2 specimens was analyzed as hexagonal, space group P63 or P63/m, and the unit cell volume increased with increase a sintering temperature. The specimens sintered at 1,175℃ showed X-ray patterns of homogeneous apatite single phase without the second phase such as La2Si2O7 and La2SiO5. The specimen sintered at 1,175℃ showed the maximum sintered density of 5.49 g/cm3. Increasing the sintering temperature, total conductivities increased, activation energy decreased and the values were 1.98 × 10-5 Scm-1 and 1.23eV, respectively.