Role of initial heat treatment of the ferrite component on magnetic properties in the composite of ferrimagnetic Co1.75Fe1.25O4 ferrite and non-magnetic BaTiO3 oxide.

We have prepared a composite of ferrimagnetic ferrite Co 1.75 Fe 1.25 O 4 and non-magnetic oxide BaTiO 3 . The ferrite composition Co 1.75 Fe 1.25 O 4 has been prepared by chemical co-precipitation and subsequently heated at different temperatures. The heat treated ferrite powder has been mixed with BaTiO 3 powder with mass ratio 1:1 and the mixed powder has been finally heated at 1000 °C to form composite material. Structural phase of the composite material has been confirmed by high quality Synchrotron X-ray diffraction pattern and Micro-Raman spectra. The grain surface morphology and elemental composition have been studied by Scanning electron microscope and Energy dispersive X-ray analysis. The distribution of magnetic exchange interactions and blocking behavior of the ferrimagnetic grains in composite samples has been understood by analyzing the temperature and magnetic field dependence of dc magnetization. Finally, information on modified micro-structure and ferrimagnetic parameters in composite samples has been obtained as the variation of annealing temperature of the ferrite component before making composite. [ABSTRACT FROM AUTHOR]