MICROSTRUCTURE, MAGNETIC PROPERTIES AND MICROWAVE ABSORPTION OF BaFe(12-x)MnxO19 MAGNETIC MATERIALS

Abstract

BaFe(12-x)MnxO19 soft magnet for absorber material applications have been produced by the variation of x = 0 and 1.5 (% mol) using a solid state reaction method. The raw materials used are barium carbonate (BaCO3), hematite (Fe2O3) and manganese oxide (MnO). The ball milled raw materials were calcined at the 02 temperature of 1000C for 2 hours and compacted using a pressure of 1.3 tonf/cm with additive of 3 wt% 0 Celuna WE-518. Compacted samples were sintered at the temperature of 1100C (2 hours). The microstructure analysis showed that the crystal structure of BaFe12O19 has been obtained with the lattice parameters of a = b = 5.865Ã…, and c = 23.099 Ã… with particle size < 2µm. The element analysis by µXRF on BaFe10.5Mn1.5O19 magnet shows that the material was consisted of Fe = 86.577, Ba = 12.433, and Mn = 0.331 (wt%). We observed that the addition of Mn was slightly reduced the magnetic flux density and decreased the magnetic remanence and coercivity. However, the BaFe(12-x)MnxO19 magnets microwave properties showed that the maximum reflection loss (RL) value on BaFe10.5Mn1.5O19 is -24.2 dB at the frequency of 8.98 GHz with optimum absorption is 99.80% at the frequency of 4.81GHz. This experiment showed that the addition of Mn to Barium Hexaferrite structure is promising for application of radar absorbing material (RAM).

Keywords : Soft Magnet, Barium Hexaferrite, Mangan Oxide, Radar Absorber Materials (RAM)