Effects of Fe2O3 content on ionic conductivity of Li2O-TiO2-P2O5 glasses and glass-ceramics

In this study, Li2O-TiO2-P2O5-x(Fe2O3) (x = 0, 2.5, 5 and 7.5 weight part) glass and glass-ceramics were synthesized through conventional melt-quenching method and subsequently heat treatment. Glass samples were studied by UV-visible spectroscopy and crystallized samples were characterized by differential thermal analysis, X-ray diffractometry and field emission scanning electron microscopy. Besides, electrical properties were examined according to the electrochemical impedance spectroscopy techniques. Experimental optical spectra of the Fe2O3-doped glasses revealed strong UV absorption band in the range of 330-370 nm, which were attributed to the presence of Fe3+ ions. The major crystalline phase of the fabricated glass-ceramics was LiTi2(PO4)(3). However, Li3PO4 was also identified as the minor one. Considering the impedance spectroscopy studies, ionic conductivity of Fe2O3 containing glasses was higher than that of the base glass. Additionally, the maximum bulk ionic conductivity of 1.38 x 10(-3) S/cm was achieved as well as activation energy as low as 0.26 eV at room temperature for x = 5. (C) 2016 Elsevier B.V. All rights reserved.