Electrospinning synthesis of Cd-substituted Ni–Co spinel ferrite nanofibers: an investigation into their structural and magnetic features

The objective of this investigation is to study the structural and magnetic properties of Ni0.5Co0.5−xCdxFe2O4 (NCCFO) (x ≤ 0.20) nanofibers (NFs) fabricated utilizing the electrospinning technique. The phase purity and the chemical composition of the synthesized NFs were confirmed by PXRD and EDX via elemental mapping analysis. The magnetic properties for diverse NCCFO NFs were analyzed by measuring the magnetization as a function of magnetic field M(H). The synthesized NCCFO NFs are found to be ferrimagnetic, and referring to the pristine Ni0.5Co0.5Fe2O4 NFs, the saturation magnetization (Ms) value rises with rising Cd content. The greatest Ms of about 38.5 emu/g was obtained for x = 0.20 NFs. The enhancement of Ms throughout the NFs up to the maximum value of x was mainly attributed to the effects of surface spins, the cations distribution, the evolution of magneto-crystalline anisotropy, and the variation of magnetic moment $$(n_{B} )$$ . All prepared NFs displayed values of squareness ratio $${\text{SR}} = M_{{\text{r}}} /M_{{\text{s}}}$$ lower than 0.5, which indicates that these NFs consist of nanoparticles (NPs) with a single-magnetic domain (SMD) structure. Compared to the pristine Ni0.5Co0.5Fe2O4 NFs, the coercive field (Hc) was increased with rising Cd content up to x = 0.10. The largest Hc value belonging to x = 0.10 product is around 1005.7 Oe; then, Hc was decreasing with a further increase in the Cd content.