Modifying Barium Hexaferrite Magnets by Adding Sol-Gel Synthesized Cobalt Ferrite Phase

Abstract

Abstract Combining various types of ferrites brings about magnetic properties desirable for different applications. This study aims to modify barium hexaferrite (BaFe 12 O 19 ) by physically mixing it with cobalt ferrite (CoFe 2 O 4 ). BaFe 12 O 19 /CoFe 2 O 4 magnets were produced by ball-milling and pressing sol-gel-derived ferrite powders. The ferrite composites showed variations in magnetic properties from BaFe 12 O 19 magnets with a saturation magnetization of 69.46 emu/g and a maximum energy product of 0.4529 MGOe. For the BaFe 12 O 19 :CoFe 2 O 4 weight ratio of 4:1, both satura-tion and remanent magnetizations were increased due to the addition of CoFe 2 O 4 with high magnetizations. However, the magnetizations were reduced when the BaFe12O19:CoFe2O4 ratio was reduced to 2:1. On the other hand, the coercivity was monotonously decreased with increasing CoFe 2 O 4 . Interestingly, the maximum energy product in this study was linearly decreased with the bulk density of the magnets from 3.59 to 3.15 g/cm 3 . It is concluded that magnetic properties could be modified from a facile physical mixing of ferrites.