HE Yao, HE Xi, JIANG Yong, LU Anxian
(School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan, China)
Abstract: The glasses and glass-ceramics in MgO-Al2O3-SiO2 system were prepared by using the traditional melt cooling method and a two-step heat treatment method, respectively. The influence of Na2O content on structure and properties of the samples were studied. It was found that, when the content of Na2O increased from 1 mol% to 5 mol%, the density, hardness and strength of the parent glass gradually decreased, while the ionic conductivity gradually increased. The glass doped with 5 mol% Na2O had an ionic conductivity of 2.9×10-8 S /cm. The main crystalline phase in the glass-ceramics from the glasses nucleated at 740 °C for 36 h and crystallized at 1020 °C for 3 h was α-cordierite. With increasing content of Na2O, the crystallinity was gradually decreased, while the ionic conductivity was gradually increased. The glass-ceramic with 5 mol% Na2O had the highest ionic conductivity, which was 1.33×10-6 S/cm. Therefore, this glass-ceramic material has potential applications as solid electrolytes.
Key words: Na2O doping, glass-ceramics, ionic conductivity, solid electrolyte