Influence of Fe2O3 on non-isothermal crystallization kinetics and microstructure of lithium titanium phosphate glass-ceramics

The crystallization behavior and microstructure of Li2O-TiO2-P2O5-Fe2O3 glass-ceramic were investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Crystallization kinetic parameters including the activation energy for crystallization (Ec) and the Avrami exponent (n) were also measured. The activation energy for crystallization was found to be 656 kJ/mol and 295 kJ/mol, respectively, in the Fe2O3-free and 5 weight ratio Fe2O3 containing glasses. The FTIR spectra revealed a strong band due to the influence of Fe2O3 content on different phosphate groups. Impedance spectroscopy studies suggest that the ionic conductivity of the glass-ceramics containing the optimized Fe2O3 content has been improved as compared with the Fe2O3 free one. According to the obtained results, LiTi2(PO4)3 precipitated as near spherical and pyramid-like crystals.