Abstract

This study addresses the synthesis and characterization of hexagonal barium hexaferrite (BaFe12O19) and strontium hexaferrite (SrFe12O19) nanoparticles, aiming to enhance their structural and magnetic properties for potential applications. Using the sol-gel method, nanoparticles were synthesized and calcinated at 1000 degrees C, 1100 degrees C, and 1200 degrees C for 5 h. A comprehensive analysis was conducted on the prepared nanoparticles' structural, functional, morphological, and magnetic properties. X-ray diffraction confirmed the hexagonal structure and single-crystal phase for BaFe12O19 and SrFe12O19 across all calcination temperatures. The Rietveld analysis of XRD patterns of all the samples have been carried. Fourier transform infrared spectroscopy identified fundamental vibrations at octahedral and tetrahedral sites, verifying the presence of characteristic functional groups. Morphological studies revealed that at an annealing temperature of 1100 degrees C, the average nanoparticle diameters were 335 nm for BaFe12O19 and 302 nm for SrFe12O19. The elemental analysis and distribution of elements of hexaferrites were studies using Energy Dispersive X-ray Analysis with color mapping method. Magnetic properties were extensively analyzed, including saturation magnetization (Ms), coercivity (Hc), retentivity (Mr), anisotropy field (Ha), squareness ratio (Mr/Ms), and magnetocrystalline anisotropy (K1). At 1100 degrees C, the magnetic properties of BaFe12O19 are Ms = 55.96 emu/g, Hc = 4308 G, Mr/Ms = 0.51, Ha = 31.30 kG, and K1 = 5.65 x 105 erg/cm3. For SrFe12O19, these values are Ms = 50.80 emu/g, Hc = 3507 G, Mr/Ms = 0.52, Ha = 21.20 kG, and K1 = 5.65 x 105 erg/cm3. Additionally, the study explored the magnetodielectric properties of BaFe12O19 and SrFe12O19 nanoparticles. At a magnetic field of 6000 G, the magnetocapacitance percentage (MC%) and magnetotangent loss percentage (ML%) for BaFe12O19 are -6.23 % and -8.85 %, respectively, while for SrFe12O19, these values are -4.38 % and -1.0 %. The findings indicate that the synthesized hexaferrite BaFe12O19 and SrFe12O19 nanoparticles exhibit significant potential for applications in sensors, permanent magnets, and data recording, with optimized structural and magnetic properties achieved at specific calcination temperatures.