Structural and Dielectric Properties of ‘Mg’ Doped M-Type Strontium Hexa-Ferrites (SrFe₁₂O₁₉) Synthesized via Sol-Gel Method

Abstract

M-type hexagonal ferrites have wide range of applications in magnetic recording media, microwave devices, micro electrochemical systems, high frequency devices, magneto-optical devices and many more. In present research, M-type strontium hexagonal ferrites doped with ‘magnesium’ having chemical composition (SrMgxFe12-xO19) for x= 0.00, 0.05, 00.10, 0.15, 0.20, were synthesized to investigate the influence of rare earth metal doping on the structure and dielectric properties via sol-gel auto combustion technique. Molecular absorption/transmission, structural properties and dielectric response were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and Dielectric measurements of ‘Mg’ doped strontium hexaferrites. X-ray diffraction analysis verified the magneto-plumbite structure. Crystal sizes were found in varying order for different concentrations of ‘Mg’ ranging from 12.357 to 15.375 nm. The FT-IR spectra exhibited higher frequency band (500–515.84 cm-1) indicating tetrahedral site’s vibrations of metallic cations and lower frequency band (385.35–375.16 cm-1) exhibiting octahedral sites due to metallic oxygen bond that confirmed the hexagonal structure. The resonance peaks were observed in dielectric constant, loss, tangent loss, AC conductivity, electric modulus and quality factor versus frequency graphs. The dielectric properties were found to be enhanced gradually by increasing concentration of magnesium. The best Q-factor was found for magnesium concentration (x=0.20). The dielectric parameters specify that these ferrite nanoparticles are good applicants for the higher frequency implementations.