Temperature Dependence of Magnetic Properties in Ferrite Powders by High Energy Ball Milling

Abstract:

The ferrite powders were prepared by high energy ball-milling, and subsequently compacted under a pressure of 490MPa for 3min and sintered at 1273~1673K for 3h. The spherical shaped initial powders with a mean size of approximately 70μm were changed to irregular shaped powders of 230nm in a mean size after milling at 300rpm for 3h. The milled powders were composed of the nanosized particles with a size of approximately 10nm. After compacting, the green density was approximately 70%. The sintered sample with a relative density of approximately 98% was obtained by sintering at 1473K, which showed the saturation magnetization (M_s) of approximately 90emu/g and the coercivtity (H_c) of approximately 19Oe at room temperature. The M_s decreased with increasing temperature, whereas the H_c and initial permeability (μ_i) were unchanged. There was no change in the M_s, H_c and μ_i during holding at 423K.

• Periodical: Materials Science Forum (Volume 804)
• Pages: 153-156
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.804.153
• Online since: October 2014
• Authors: Chan Seok Hong*, Yo Seung Song, Si Young Chang
• Keywords: Ferrite Powder, High Energy Ball Milling, Magnetic Property, Nanoparticle, Relative Density

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