Novel Molten Salt Assisted Autocombustion Method for the Synthesis of Aluminum-Doped SrFe12-xAlxO19 Hexaferrite Nanoparticles

The study presents a novel molten salt assisted autocombustion synthesis of SrFe12-xAlxO19 particles. The extrinsic magnetic properties such as coercivity and the remanence of sintered M-type ferrites are highly dependent on the microstructure viz. morphology and size, of the ferrite particles. The control of the microstructures of ferrite particles is usually achieved via control nucleation and grain growth process. In this study, NaCl salt was used to control the crystal shape and size of Al3+ doped SrFe12-xAlxO19 particles. The presented novel method couples advantage of deriving homogenized particles via auctocombustion first and later sintering in the presence of NaCl salt. Highly dispersed, homogeneous, and hexagonal shaped SrFe12-xAlxO19 ferrite particles were achieved with this method. The particles derived via the molten salt assisted method presented a high coercivity and squareness ratio (>0.5) as compared to that obtained via autocombustion method only.