Influence of precursor and salt assisted calcination on magnetic properties of Sr-ferrites

Hexagonal Sr-ferrites were synthesized via salt assisted spray drying method to control the agglomeration and grain growth of particles. The effect of precursor solution on crystalline growth, morphology and magnetic properties have been investigated. The particles size was of nano to submicron scale and non-agglomerated in NaCl salt matrix. The dispersibility and solvent inductivity of salt matrix in the different annealing temperature control the crystalline growth. The Sr-ferrites prepared from sol solution annealing at 750 °C demonstrate a coercivity of 6042 Oe and magnetization of 47.3 emu/g. The optimum magnetic properties prepared via no-treatment precursor solution and subsequent molten salt assisted annealing at 850 °C show a coercivity of 5927 Oe and magnetization of 57.6 emu/g. This will possibly enable a large scale to generate Sr-ferrites for a wide-range application via controlling precursor solution and annealing process.