Microstructural Characteristics and Magnetic Properties of Al-Substituted Barium Hexaferrite Nanoparticles Synthesized by Auto-Combustion Sol-Gel Processing

摘要

Substituted barium hexaferrite ceramics BaFe12-x Al (x) O-19 (x = 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0) were prepared via auto-combustion sol-gel method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), and vibrating sample magnetometry (VSM) were used to investigate the effect of Al3+ ion substitution contents on structural characteristics and magnetic properties of barium ferrite. The results show the hexagonal phase is formed in all of the samples, and with the substitution of aluminum cations in the hexagonal structure of barium ferrite, the particle size is reduced to lower than the single domain critical size. It was found that with an increase in the substitution of Al3+ ions, the saturation magnetization (M (s)) decreased from 62 to 14 emu/g, while the coercive field (H (c)) increased from 2.7 kOe at x = 0 to 6.1 kOe at x = 1.5 and then, at higher Al3+ ion contents (x > 1.5), decreased.