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 × 10⁻³ S/cm was achieved as well as activation energy as low as 0.26 eV at room temperature for x = 5. - Highlights: • Bulk and total ionic conductivity was extracted by using impedance spectroscopy. • Ionic conductivity of the studied glasses and glass-ceramics increased with increasing Fe₂O₃ content. • The highest bulk ionic conductivity at room temperature was found to be 1.38 × 10⁻³ S/cm for GC₅.