The silicate oxyapatites Ca2-3xLa8+2x□x（SiO4）6O2 （x=0, 0.17, 0.33, 0.50, 0.67） was synthesized via a sol-gel method at low temperature. The apatite phases have been characterised by X-ray diffraction （XRD）, con...The silicate oxyapatites Ca2-3xLa8+2x□x（SiO4）6O2 （x=0, 0.17, 0.33, 0.50, 0.67） was synthesized via a sol-gel method at low temperature. The apatite phases have been characterised by X-ray diffraction （XRD）, conducting properties was studied by electrical chemistry impedance spectroscopy （EIS）. The conductivity of La9.33□0.67（SiO4）6O2 is 1.58 × 10-3 S·cm-1 at 700 ℃, it is higher about 4 270 times than that of Ca2La8（SiO4）6O2, the activation energy is decreasing from 1.37 eV to 0.84 eV. With cation vacancies increasing,the conducting mechanism is gradually translation from a direct linear pathway free oxygen ion conduction to a curve pathway interstitial oxygen ion conduction. The electrical conductivities is almost independent of the oxygen partial pressure, this suggests that the oxyapatites exhibited almost pure O2- ion conduction over a wide range of oxygen partial pressure.展开更多
文摘The silicate oxyapatites Ca2-3xLa8+2x□x（SiO4）6O2 （x=0, 0.17, 0.33, 0.50, 0.67） was synthesized via a sol-gel method at low temperature. The apatite phases have been characterised by X-ray diffraction （XRD）, conducting properties was studied by electrical chemistry impedance spectroscopy （EIS）. The conductivity of La9.33□0.67（SiO4）6O2 is 1.58 × 10-3 S·cm-1 at 700 ℃, it is higher about 4 270 times than that of Ca2La8（SiO4）6O2, the activation energy is decreasing from 1.37 eV to 0.84 eV. With cation vacancies increasing,the conducting mechanism is gradually translation from a direct linear pathway free oxygen ion conduction to a curve pathway interstitial oxygen ion conduction. The electrical conductivities is almost independent of the oxygen partial pressure, this suggests that the oxyapatites exhibited almost pure O2- ion conduction over a wide range of oxygen partial pressure.
