Investigation of Synthesis and Ionic Conductivity of Na5Ysi4O12

Single-phase Na₅YSi₄O₁₂(NYS) was prepared by both conventional solid state reaction and sol-gel process. The formation of NYS was monitored by means of X-ray diffraction (XRD) and scanning electron microscope(SEM) techniques. The thermal stability of major impurity phases corresponding to different polymerization states of silicon was discussed. The conditions for preparing single-phase NYS ceramic with a high ionic conductivity were given.