Influence of ferric oxide on the crystallization of Li–Zn ferrite anorthite and hematite phases at low temperature ceramic glaze

The crystallization mechanism and properties of lithium zinc ferrite (LiZnFe2O4) anorthite (CaAl2Si2O8) and hematite (α-Fe2O3) of ceramic glaze containing Li2O and ZnO system were studied as a function of Fe2O3 contents. The glaze was fired at 1100 °C and the addition of 5–25 wt.% Fe2O3 contents developed brown color crystals. A non-isothermal analysis was performed to study the crystallization behavior of LiZnFe2O4 anorthite and hematite using DTA with various heating rates for calculating activation energy and Avrami constant from Kissinger and Augis–Bennett equation. XRD, SEM/EDS and Raman spectroscopy were used to determine the crystalline phases. The occurrence of LiZnFe2O4 anorthite and hematite depended on the Fe2O3 content in the glaze. In the case of 15 wt.% Fe2O3 demonstrated the main crystalline phase of LiZnFe2O4. Furthermore, anorthite and hematite were also found in 25 wt.% Fe2O3 content. The values of Avrami constant were 0.9 and 0.5, and the surface crystallization tendency is dominant for these crystalline phases.