Fabrication and Conductivity of La_(9.33)Si_6O_(26)-based Composite Oxygen-ionic Conductor

The oxygen-ionic conductor of La9.33Si6O26-10wt% Zr0.86Y0.14O1.92 composite material was prepared by using a modified co-precipitation method.X-ray diffraction,scanning electron microscope and complex impedance were adopted to investigate the phase component,microstructures and conductivities of the composite material,re-spectively.The results show that the average grain size of the as-calcined powder is 35 nm and the average particle size of the as-sintered composite ceramic is about 500 nm.The conductivities of the composite ceramic are higher than those of the single phase La9.33Si6O26 and Zr0.86Y0.14O1.92 ceramic at the temperatures from 300℃ to 700℃.The conductivity of the composite ceramic is one order in magnitude higher than that of polycrystalline La9.33Si6O26 at 700℃.The conduction mechanism of the composite material is discussed by the analysis of impedance spectra and electric modulus spectra.