La_9(SiO_4)_(6-x)(VO_4)_xO_(1.5+0．5x)的合成及其导电性能的研究

Synthesis and Conducting Properties of La_9(SiO_4)_(6-x)(VO_4)_xO_(1.5+0.5x)

利用溶胶-凝胶法低温合成了钒掺杂硅酸盐氧基磷灰石La9(SiO4)6-x(VO4)xO1．5+0.5x (x=0、0．5和1),经XRD表征所得产品为磷灰石相．以电化学阻抗谱研究了其导电性能,V的掺杂使电导率大大提高,700℃时La9(SiO4)5(VO4)O2电导率为5．23×10-3S·cm-1,与未掺杂V的La9(SiO4)6O1．5相比提高了5倍．氧分压Po2=105-1Pa时,La9(SiO4)6O1．5的电导率不改变,而La9(SiO4)5(VO4)O2的电导率则随着氧分压的降低而稍有增加,表明钒的掺杂在体系中引入n型电子导电．

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 800℃. 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× 10^3S·cm^-1 at 700℃, 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.