Correlation between structural and improved magneto-dielectric behaviour of Li-Mg-Dy ferrite/Graphene nanoplatelet composites and their potential applications

Abstract

The tenacity of the current study was to prepare Li0.2Mg0.6Fe2.17Dy0.03O4/Graphene nanoplatelet (LMFD/GNP) composites with different Graphene nanoplatelets (GNPs) contents, including 0 wt% GNPs, 1.25 wt% GNPs, 2.5 wt% GNPs, 3.75 wt% GNPs, and 5 wt% GNPs using an economical chemical sol–gel auto combustion (SGAC) process, with a balance among the structural, and magneto-dielectric order parameters for potential applications. The structural study indicated all the LMFD/GNP composites have single-phase spinel matrix and maximum crystallite size was 53.32 nm, while Lorentz fit Raman spectra also confirmed the spinel matrix along with the existence of GNPs in the composites. The LMFD/GNP composites revealed a decrease in dielectric constants and tangent loss with increasing frequency and higher values at low frequencies, while lower values at high frequencies. The quality factor was maximum and tangent loss was the minimum for LMFD/GNP composite with GNPs doping 1.25 wt% GNPs. The LMFD/GNP composites were found to have a soft magnetic nature and the composite with GNPs concentration of 2.5 wt% GNPs has the highest saturation magnetization (104.59 emu/g) and microwave operating frequency (23.12 GHz). Moreover, the retentivity and high coercivity were 32.85 emu/g and 107.99 Oe for 1.25 wt% GNPs composite. Due to a comparatively high crystallite size, large saturation magnetization, and microwave operating frequency along with high coercivity the LMFD/GNP composites are well suited for potential applications including high-frequency devices, transformer cores, and hyperthermia.