Dependence of magnetic properties on crystallite size of CoFe₂O₄ nanoparticles synthesised by auto-combustion method

Figures & data

Figure 1. The FTIR spectrum of the as-burnt powder.

Figure 2. The XPS core spectra of (a) Fe and (b) Co.

Figure 3. (a) The XRD patterns of the as-burnt powder and the sample annealed at 300, 400, 600, 700, 900 and 1200°C, respectively. (b) Particle size and lattice constant vs. annealing temperature.

Figure 4. The Raman spectra of the samples annealed at temperature from 300 to 1200°C.

Figure 5. (a) The TEM images of the CoFe₂O₄ nanoparticles annealed at 400°C. (b) The selected diffraction patterns of the same sample.

Table 1. Values calculated from the SAD pattern of the CoFe₂O₄ nanoparticles annealed at 400°C.

hkl	111	220	311	400	422	511	400
d hkl(nm)	0.49	0.30	0.25	0.21	0.172	0.161	0.148

Figure 6. Dependence of (a) H _c, (b) M _s and (c) remanence ratio on the annealing temperature.