Publication Date:
2016-12-01
Description:
We report on a comparative study of high performance isotropic cobalt ferrite (CoFe 2 O 4 ) powder processed by dry and surfactant assisted (wet) ball milling. Milling times as short as 1.5 min (dry) and 6 min (wet) have resulted in a 4-fold increase in coercivity, with a maximum achieved value above 318 kA/m (4 kOe). The use of surfactant is shown to be advantageous in the formation of a more homogeneous structure constituted by non-agglomerated and strained nanoparticles. A record ( BH ) max value of 18.6 kJ m − 3 (2.34 MGOe) has been obtained for isotropic powder after post-processing annealing. This magnetic performance combined with the required short processing times and the unnecessary requirement of oxygen avoidance in the milling process, makes this CoFe 2 O 4 powder a good candidate for permanent magnet applications.
Print ISSN:
0003-6951
Electronic ISSN:
1077-3118
Topics:
Physics
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