Microstructure and magnetic properties of barium hexaferrite produced by sol gel auto combustion for radar absorber material(RAM) application

Barium hexaferrite (BaFe₁₂O₁₉) with hexagonal structure has been known as the high performance magnetic for Radar Absorber Material (RAM). Barium hexaferrite (BaM) was synthesized by sol gel auto combustion to get an homogeneous nanoparticle of BaM. Barium hexaferrites obtained from solution mixture between barium nitrate and ferri nitrate nonahidrat with precipitation of ion barium (Ba_{2 +}) and ferri (Fe_{3 +}) by solution of sodium hydroxide. Sample prepared with mol ratio of Fe/Ba 11 then added ammoniac in order that pH varies become 7,5; 9; and 11. Citric acid added in order that happen process of combustion. The stirring time was varieties by 1, 2, 3 hours. The effect of pH, stirring time, microstructure, phase,and magnetic properties were investigated using X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and a vibrating sample magnetometer (VSM). The results showed that the highest coercivity was 0.6 Tesla and the smallest crystal size 414.409 nm was obtained for pH 7.5 and stirring time 2 hours. The largest magnetic saturation 55.54 emu /g was reached for pH 7.5 with stirring time 1 hour.