Correlation between the composition, structural parameters and magnetic properties of spinel-based functional nanocomposites

Abstract

The “soft/soft” (CoFe 2O4)x/Ni0.4Cu0.2Zn0.4Fe2O4)y nanocomposites (NCs), as a function of the phase ratio, have been synthesized via the green sol–gel method using 6 dates. The correlation between chemical composition, structural parameters and magnetic properties was investigated. The average crystallite size (Dmax) of the products was found to be within the range of 24.6-41.1 nm. It was observed that an increase in the CoFe 2O4 content leads to an increase in the most probable size of the coarse fraction and a decrease in the most probable grain size of the fine fraction. As the (Ni0.4Cu0.2Zn0.4)Fe2O4 content increases, the average size of the fine and coarse fractions decreases. The magnetic properties were investigated in a wide magnetic field range (80 kOe) at 300 and 10 K. The maximum magnetization saturation or Ms (∼124.3 emu/g at 10 K and ∼81.2 emu/g at 300 K) was observed for the sample with the ratio 1/2 that was ∼30% higher than Ms for the pure (Ni0.4Cu0.2Zn0.4)Fe2O4 ferrite at 10 K (∼86.9 emu/g) and ∼35% higher than at 300 K (∼52.8 emu/g). This fact clearly demonstrates the presence of a synergetic effect in the NCs. The dominance of low-temperature Ms values was explained by the lack of thermal energy of the disordered spin. The presence of a synergetic effect in the (CoFe 2O4)x/Ni0.4Cu0.2Zn0.4Fe2O4)y NCs can be observed due to a strong coupling between the two magnetic phases, according to careful analysis of the correlation between the chemical composition, structural parameters and magnetic properties.