Enhancement of the Magnetic Properties for Co-Mn-Zn Ferrites

Aluminum substituted cobalt manganese zinc ferrite nanoparticles Co0.425Mn0.425Zn0.150AlxFe2-xO4 (from x= 0.0 to 0.15 with step 0.025) have been synthesized by chemical co-precipitation route. X-ray diffraction (XRD) and infrared spectroscopy (FTIR) revealed that the obtained powders have a single phase of cubic spinel structure. The crystallite sizes calculated from XRD data have been confirmed using transmission electron microscopy (TEM) photographs showing that, the powders are consisting of nanosized grains with an average size around 19 nm independent on the Al-content. Magnetic hysteresis loops were traced at room temperature using VSM. It was found that due to the Al ions substitution, the values of saturation magnetization MS for samples with x ≤ 0.075 were improved. Whereas, both coercive field HC and remnant magnetization Mr were decreased with increasing the Al-content. The obtained results were discussed in the light of non-collinear spin structure in the B-sites (Yafet-Kittle type of spin arrangement).