Role of aluminium doping in tailoring the structural, electrical, and magnetic characteristics of Li-Co ferrites using sol-gel auto-combustion synthesis

This study examined the impact of aluminium doping on the structural, electrical, and magnetic properties of Li(0.5)Co(0.75)AlxFe(2−x)O4spinel ferrites (x= 0.15 to 0.60). The samples were synthesised using the sol-gel auto-combustion technique, and they were examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fouriertransform infrared spectroscopy (FTIR), dielectric measurements, and vibrating sample magnetometry (VSM). All samples possessed a single-phase cubic spinel structure with Fd-3m space group, according to XRD analyses. SEM images showed the creation of homogeneous particles with an average size of about 21 nm. All samples had spinel ferrite phases, confirmed from FTIR spectra. DC electrical conductivity studies showed that the conductivity increased with increasing aluminium content up tox= 0.45 before dropping atx= 0.60. The maximum saturation magnetization value was found atx= 0.45, according to VSM measurements, which demonstrated that the magnetic characteristics were strongly correlated with the amount of aluminium.