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.
