INVESTIGATIONS INTO PHASE-FORMATION OF LIFE5O8 FROM DECOMPOSED FREEZE-DRIED LI-FE-FORMATES

Lithium ferrite (LiFe5O8) was prepared by decomposition of a freeze-dr ied Li-Fe-formate precursor at unusually low temperatures of 250-degre es-C-700-degrees-C. The phase formation processes are studied by means of X-ray powder diffraction, IR-spectroscopy, Mossbauer spectroscopy and magnetic measurements. The decomposition of the Li-Fe-formate at 2 50-degrees-C produces a spinel phase similar to gamma-Fe2O3. Insertion of Li+ ions into the gamma-Fe2O3 lattice and cation ordering processe s take place on thermal treatment in the temperature range from 300-de grees-C-700-degrees-C without an intermediate formation of alpha-Fe2O3 . At 700-degrees-C a pure crystalline lithium ferrite with the expecte d magnetic properties is obtained.