Authors: Qingle Shi Lihua Lu Yanwei Zeng Hua Zhang
Publish Date: 2012/10/31
Volume: 27, Issue: 5, Pages: 841-846
Abstract
The apatitetype lanthanum silicates with formula La933Si6O26 are prepared by solgel process The homogeneity of the sol affected by pH value of the solution is investigated The viscosity of the sols slightly increases first and then increases abruptly because the predominant reaction mechanism changes from hydrolysis reaction to condensation reaction In addition the onset time of the increase for the viscosity shortens from pH 1 to pH 4 The gelation time decreases with increasing pH of the solution Therefore the pH of the sols should be less than 4 to form gel The sol with initial pH 2 shows maximum value of zeta potential and maximum stability For the sample with initial pH 2 pure apatitetype lanthanum silicates La933Si6O26 have been successfully prepared after the dried gel is calcined at 1 000 °C In addition this sample sintered at 1 550 °C exhibits the highest ionic conductivity The activation energies are all less than 090 eV
Keywords: