Investigations into phase formation of LiFe5o8 from decomposed freeze-dried Li-Fe-formates

Lithium ferrite (LiFe5O8) was prepared by decomposition of a freeze-dried Li-Fe-formate precursor at unusually low temperatures of 250 °C–700 °C. The phase formation processes are studied by means of X-ray powder diffraction, IR-spectroscopy, Mo¨ssbauer spectroscopy and magnetic measurements. The decomposition of the Li-Fe-formate at 250 °C produces a spinel phase similar to γ-Fe2O3. Insertion of Li+ ions into the γ-Fe2O3 lattice and cation ordering processes take place on thermal treatment in the temperature range from 300 °C–700 °C without an intermediate formation of α-Fe2O3. At 700 °C a pure crystalline lithium ferrite with the expected magnetic properties is obtained.