Influence of Al3+doping on structural and magnetic properties of CoFe2-xAlxO4Ferrite nanoparticles


A series of Al3+substituted CoFe2-xAlxO4(x = 0.0 to 0.9) ferrite nanoparticles were synthesized via autocombustion method. XRD data show that all the samples exhibit single phase cubic spinel structure where the lattice parameter was observed to decrease linearly with increasing Al3+content. Structurally Al3+doping was observed to bring in grain refinement and increase dislocation density in CoFe2-xAlxO4. The magnetic parameters namely saturation magnetization, MS, coercive field, HC, and remanent magnetization, Mrvary significantly with Al3+doping. The Al3+doping resulted in reduction in Ms and Hc due to magnetic dilution effect and reduction in anisotropy constant K1, respectively. Room temperature Mössbauer spectra were analyzed to extract cation distribution and hyperfine parameters. The hyperfine magnetic field decreases at both tetrahedral (A) and octahedral (B) interstitial sites with the increase in Al3+content. The Mössbauer spectral analysis reveals that Al3+has preference for the tetrahedral A site and Co2+prefers B sites.

Publication Title

Journal of Alloys and Compounds