The effects of raw materials particle sizes on the solid-state reaction progress, morphology and magnetic properties of M-type strontium hexaferrites

In this work, the effects of SrCO3 3 and Fe2O3 2 O 3 particle size on the reaction process, morphology and magnetic properties of M-type strontium hexaferrites (SrM) have been further studied. Pure strontium hexaferrite magnetic degrees sample based on SrCO3 3 and Fe2O3 2 O 3 molar ratio of 1:6 has been successfully prepared at 1150 C. The results indicated that Fe2O3 2 O 3 particle size was the main factor of affecting the formation of SrM, a pure SrM phase magnetic sample was able to obtain at lower calcination temperatures by using fine Fe2O3 2 O 3 powder as raw material, and at the same calcination temperature, a sample using fine Fe2O3 2 O 3 powder as raw material was able to obtain pure SrM phase magnetic sample with shorter holding time. When the mean particle size of Fe2O3 2 O 3 was degrees below 60 nm, a pure SrM phase magnetic sample was able to form at 1150 C at a molar ratio of 1:6 of SrCO3 3 and Fe2O3. 2 O 3 . In this case, the magnetic parameters of the sample with the optimum magnetic parameters were saturation magnetization M S = 77.8 emu/g and coercive force H C = 4122 Oe. And the solid-state reaction process of the corresponding samples was slightly faster when the mean particle size ratio of Fe2O3 2 O 3 and SrCO3 3 was between 0.35 and 0.36. Assuming that a SrCO3 3 particle is surrounded by Fe2O3 2 O 3 particles, it can be inferred that the corresponding molar ratio of Fe and Sr of the nearest raw material particles is between 3.6 and 3.8.