Innovative Nanostructuring of Li–Zn ferrite/graphene composites with tunable properties

Abstract

The Li-ferrite and graphene oxide (GO) nanocomposites, denoted as (Li0.5-x/2ZnₓFe2.5-x/2O4: x = 0.25), were produced through ultrasonication. The wet method generated Li-ferrite, while the Hummers' method synthesized the GO. X-ray diffraction (XRD) was used to validate the development of Li-ferrite and GO in the nanocomposites. The dimensions of the crystal were determined between 41 and 52 nm, and the porosity of the composites increased with the higher quantity of GO. The scanning electron micrographs (SEM) of ferrites illustrated the formation of uniform and well-defined grains with consistent shapes, exhibiting properties well-suited for effective microwave absorption. The electrical resistance of spinel ferrite was measured at approximately 3.34 × 1011 Ω-cm and significantly lowered as the fraction of GO increased at ambient temperature. As per Maxwell Wagner's model, the electrical permittivity exhibited interfacial polarization with distinct real and imaginary components. The AC conductivity exhibited a positive correlation with the GO content due to the conductive properties of GO and the improved charge hopping mechanism. The frequency exponent parameter's value falls from 0.36 to 0.95 b y the Jonscher's Power law. The magnetic susceptibility of all the samples exhibited a progressive decrease as the temperature increased. The choice of using lithium-based ferrite as filler is made to strengthen the ferrite/GO composites and improve their magnetic and electrical properties. This is undertaken to harness these composites for high-frequency applications, such as their use as microwave absorbers in microwave devices.