Enhancing the magnetic and dielectric properties of M type strontium hexaferrite nanoparticles via aluminum substitution: a sol-gel synthesis approach
Shreepad S. Atkare, Sagar E. Shirsath, Khalid Mujasam Batoo, Muhammad Farzik Ijaz, Vidya J. Deshmukh, R.H. Kadam, Maheshkumar L. Mane
Abstract
Abstract This research evaluates the impact of aluminum (Al) substitution on the properties of strontium hexaferrite (SrFe 12 O 19 ) nanoparticles synthesized via a sol-gel method. A comprehensive suite of characterization techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Brunauer Emmett Teller (BET) surface area analysis, vibrating sample magnetometry (VSM), and dielectric measurements were employed. The Rietveld refinement confirmed the formation of a pure hexagonal phase (space group P63/mmc) devoid of any secondary phases. With increasing Al content, a reduction in X-ray density and lattice parameters was observed, which correlates with changes in the Raman spectral features, notably the pronounced A1g peak between 670–710 cm −1 . SEM analysis revealed a uniform distribution of grain size. This study also found that greater Al concentrations increase coercivity while reducing both the saturation magnetization and magneton number, reflecting the substitution of nonmagnetic Al 3+ ions. Additionally, the dielectric properties of both undoped and Al-doped samples demonstrated a typical exponential decline in dielectric constant with increasing frequency, showcasing their potential for various advanced magnetic and electronic applications. Graphical Abstract