Mixed-metal carbonates as precursors for the synthesis of nanocrystalline Mn-Zn ferrites

A mixed MnZnFe carbonate was prepared by precipitation of metal ions with ammonium carbonate and control of pH=7. Nanocrystalline MnZn ferrite powders were synthesized by thermal decomposition of the carbonate precursor at 500 degrees C in air. The mean crystallite size of the ferrite particles is 14 nm with a specific surface of 74 m(2)/g. The magnetization at 5 K of the MnZn ferrite powders (66 emu/g) is smaller than the saturation magnetization of the bulk material. Hysteresis loop measurements indicate ferrimagnetic behavior at 5 and 298 K with a small coercivity at room temperature. (C) 2010 Elsevier B.V. All rights reserved.