磷灰石型硅酸镧的合成与Pr掺杂的研究

Investigation of the preparation of apatite-type lanthanum silicate and its doping with praseodymium

采用溶胶凝胶法合成了Pr掺杂磷灰石结构硅酸镧La10-xPrxSi6O27-1.5x.采用TG/DTA研究了硅酸镧干凝胶的热行为.采用XRD表征了合成产物的相组成.使用交流阻抗法测定了400～800℃温度区间的电导率,结果表明Pr掺杂使电导率增大,这可能是烧结密度增大的缘故.SEM观测烧结试样的微观结构表明,在1 580～1 600℃空气中烧结不完全.

Apatite type lanthanum silicate doped with praseodymium La10-xPr3Si6O27-1.5x. was synthesized by a sol-gel technique. Thermal behavior of the dried gel of lanthanum silicate was studied with TG/DTA. The phase formation of the products was characterized by Xray diffraction（XRD）. The eleetrical conductivity of the sintered samples were investigated with the complex impedance spectroscopy measurements in the range of temperature from 400 to 800 ℃. The results showed that the conductivity increased with the Pr doping, which may be caused by density increasment of the sintered sample. The examination of microstructure of samples by scanning electron microscopy（SEM） implied that the sintering at 1 580 -1 600 ℃ in ambient air is not completed.