MN(III) CONTAINING FERRITES IN THE SYSTEM LI0.5FE2.5-XMNXO4

The decomposition of freeze-dried Li-Mn(II)-Fe(III)-formate precursors at temperatures in the region of 600 degrees C - 900 degrees C in air yields complex oxides Li0.5Fe2.5-xMnxO4 (0 less than or equal to x le ss than or equal to 1.5) with cubic spinel structure. These ferrites c ontain Mn(III) ions on octahedral sites of the spinel lattice. The cat ion distribution and the properties of the single phase LiMn-ferrites with x = 0.5, 1.0 and 1.5 were studied by X-ray powder diffraction, in frared spectroscopy, Fe-57-Mossbauer spectroscopy and magnetization me asurements. In contrast to the lithium ferrite (Li0.5Fe2.5O4, x=0), wh ere the Li ions only occupy octahedral sites, the Li ions in the Li-Mn -ferrites are found on both octahedral and tetrahedral cationic positi ons of the spinel lattice.