Influence of different complexing agents on structural, morphological, and magnetic properties of Mg–Co ferrites synthesized by sol–gel auto-combustion method

In the preparation process of magnesium-cobalt nano-ferrite powder (Mg0.1Co0.9Fe2O4) by sol–gel self-propagation method, the effect of complexing agent on the nanostructure and magnetic properties of ferrite is studied by changing the type of complexing agent (the complexing agent includes citric acid, oxalic acid, tartaric acid, glucose, and egg white). The XRD pattern of each sample has eight distinct characteristic peaks, and the number of the strongest peak in each map is one [i.e., (311) peak]. All these evidences can preliminarily indicate that the sample has a spinel structure. In addition, in the FTIR of the sample, it can be seen that there are several distinct characteristic peaks at 580 cm−1 (i.e., Fe–O peak, etc.) which can also prove the structural characteristics of the sample. In the SEM map, the sample can be seen to have an elliptical shape with a crystalline grain size between 28 and 50 nm. From this, we can guess that the complexing agent participates in the reaction and has a certain influence on the particle size of the sample. Elemental analysis showed that all the six samples prepared contained magnesium, cobalt, iron, and oxygen, and then we quantitatively analyzed the sample to find that the prepared sample was the target product. The BET test shows that a sample is prepared with glucose as the complexing agent, the specific surface area of it can be increased. The VSM data show that magnesium–cobalt ferrite powder with high saturation magnetization, residual magnetization, and coercivity can be prepared by selecting glucose as the complexing agent.