Enhancement of Magnetic and Microwave Absorbing Properties of [Ba (Fe, Mn, Ti) 12O19]1-x/[CoFe2O4] x (x = 0.2; 0.5; 0.8)Composites
L. Darmawan,Suparno, A.Manaf*
Universitas Indonesia
Abstract
In this paper, we report magnetic and microwave absorbing properties of magnetic based nanocomposites, which synthesized through mechanically alloyed the magnetic crystalline powders. The first component of composite was Mn andTi doped Barium hexaferrite (BaFe12O19) or BHF obtained through a mechanical alloying process which was mixed with the second component of mechanically alloyed the CoFe2O4 magnetic compound to form composites of [Ba (Fe, Mn, Ti) 12O19]1-x/[CoFe2O4] x (x = 0.2; 0.5; 0.8) compositions. Prior to composite the two magnetic components, the remanence and saturation magnetization of the components were obtained optimally. Before Mn-Ti doping, the BHF has remanence (Mr) and saturation magnetization 0.206 T and 0.42 T respectively, with the corresponding coersivity (Hc) was 263.1 kA/m. On the other hand, CoFe2O4 (CFO) which has a high saturation magnetization (0.48 T) but with a low coersivity (16.22 kA/m). In form of magnetic composite, the high remanence was almost retained, but with the coercivity value decreased further to the lowest 80.82 kA/m. These two main properties (high remanence and low coercivity) were led the composite being good candidates for microwave absorbing materials. Microwave absorbing characteristics of [Ba(Fe,Mn,Ti)12O19]1-x/[CoFe2O4]x (x = 0.2; 0.5; 0.8) composites were discussed inthis paperin relation with their corresponding magnetic properties for designing the best microwave absorbing materials.
Keywords: Cobalt ferrite, Barium Hexaferrite, mechanically alloying, magnetic properties, microwaves absorbing material, nanocomposite magnet.
Topic: Material Science and Engineering