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Hollow spheres of hexagonal ferrite BaCo2Fe16O27 were fabricated through a spray pyrolysis technique using co-precipitation ferrite powder precursor as materials, followed by calcinations in an air atmosphere. The phase composition, micro-morphology, and static magnetic property of the particles were measured by XRD, SEM, and VSM. The results indicate that the method for preparation of ferrite hollow microspheres (FHM) results in a broad particles size distribution. The density of FHM decreased from 5.31 g/ cm3 to 2.31 g/cm3. When the heating rate was 5 ℃/min, and temperature was 1 200 ℃ for 4 hours, pure W-type ferrites were formed. With the heat treatment temperature and time increasing, the crystal structure becomes perfect, the saturation magnetization is increased and the coercive force is decreased.
Hollow spheres of hexagonal ferrite BaCo2Fe16O27 were fabricated through a spray pyrolysis technique using co-precipitation ferrite powder precursor as materials, followed by calcinations in an air atmosphere. The phase composition, micro-morphology, and static magnetic properties of the particles were measured by XRD The results indicate that the method for preparation of ferrite hollow microspheres (FHM) results in a broad particle size distribution. The density of FHM decreased from 5.31 g / cm3 to 2.31 g / cm3. When the heating rate was 5 ℃ / min, and temperature was 1 200 ℃ for 4 hours, pure W-type ferrites were formed. With the heat treatment temperature and time increasing, the crystal structure became perfect, the saturation magnetization is increased and the coercive force is decreased.