Characterization of the Thermal Behavior of Li-Fe-Tartrate Gels (Molar Ratio Li/Feless than 1/5)

The differential thermal analysis/thermogravimetric analysis characteristics of Li-Fe xerogels prepared by the tartrate gel technique are examined. Monophase lithium ferrospinel powders can be obtained by adjusting the calcining temperatures at 200-300°C and 550°C for the xerogel, if alpha-Fe2O3 was absent during the processing. The former temperature range resulted from the thermal reaction of gamma-Fe2O3 with lithium. The latter was attributed to the thermal reaction of Li-containing gamma-Fe2O3 (Li-gammaFe2O3) with lithium. An increase in the amount of the former formed can substantially decrease that for the latter. The thermal reaction for forming lithium ferrite can be topo-tactic. More importantly, it may be triggered by the phase transformation.