Synthesis and Conducting Properties of La9(SiO4)6-x(VO4)xO1.5+0.5x
La9(SiO4)6-x(VO4)xO1.5+0.5x的合成及其导电性能的研究

The V-doped silicate oxyapatites La9(SiO4)6-x(VO4)xO1.5+0.5x (x=0, 0.5 and 1) were synthesized successfully via a sol-gel method at 800circC. The apatite phases were characterized by X-ray diffraction (XRD). Conducting properties were studied by electrochemical impedance spectroscopy (EIS). It is found that the conductivities are influenced by increasing vanadium content, the conductivity of La9(SiO4)5(VO4)O2 is 5.23×times 10-3S·cm-1 at 700circC, it is about 5 times higher than La9(SiO4)6O1.5. The electrical conductivity of La9(SiO4)6O1.5 is almost independent of the oxygen partial pressure from 105 to 1Pa, but that of La9(SiO4)_5(VO4)O2 is minor increased. This result may indicate n-type electron conduction generated in the vanadium doped system.