Mn-Zn ferrite with higher magnetization for temperature sensitive magnetic fluid

A growth-assisted coprecipitation process is proposed to achieve highly magnetic Mn-Zn ferrite particles. In this method, first, the particles were synthesized by coprecipitation under optimum condition. Then, further enhancement in particle size was obtained by using the already prepared particles as seed. The average crystallite size of the particles prepared by the proposed method was 12 nm. Furthermore, the magnetization at 1 T applied field was 50 emu/g compared to 37 emu/g of coprecipitated particles. It should be noted that the Curie temperature of the particles remained similar to the coprecipitated particles suggesting that the composition of the Mn-Zn ferrite particles has not been affected by the modified synthesis technique. The gradient of the magnetization-temperature curve was enhanced as a consequence of the rise in magnetization. These particles could be used for the synthesis of temperature sensitive magnetic fluid with higher magnetization and magnetization-temperature gradient. (C) 2003 American Institute of Physics.