Ionic conductivity and microstructural evaluation of Li2O–TiO2–P2O5–SiO2 glass-ceramics

Abstract Conductive glass-ceramics based on the Li 2 O–TiO 2 –P 2 O 5 –SiO 2 system were fabricated by heat-treatment at the temperature interval of 700–1000 °C for 2 h. Based on the obtained results, the prepared glasses showed a tendency for bulk crystallization of LiTi 2 (PO 4 ) 3 and TiO 2 as the major and minor crystalline phases, respectively. The crystallization behavior of glass-ceramics was monitored by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods; and their conductivity behavior was evaluated by complex impedance technique. It was shown that, the ionic conductivity of the glass-ceramic was enhanced by increasing the heat treatment temperature from 700 to 950 °C. This tendency was attributed to the growth of LiTi 2 (PO 4 ) 3 crystals. The highest room temperature conductivity of 7×10 −4  S/cm was obtained after crystallization at 950 °C for 2 h. By increasing the heat treatment temperature above 950 °C, the conductivity was decreased, probably due to the microcracking of the specimen as the result of grains growth.