Ni and Zn Substituted M-type Barium Hexaferrite Processed by Sol-Gel Auto Combustion Method

Barium hexaferrite (BaFe₁₂O₁₉) or BaM was synthesized by sol-gel auto combustion method with the new dopan elements, Ni and Zn, with mole fraction (0.2, 0.4, 0.6), pH (7, 9, 11) and sintering temperature (850, 950, 1050 °C) for 3 hours. Ni - Zn ions were substituted to Fe³⁺ ion of BaM in order to modify the magnetic properties such as magnetic saturation (Ms) and coercivity (Hc). Magnetic properties and microstructure were characterized by various instruments; XRD, SEM, FTIR, and VSM. It was obtained that the largest crystal size of BaM (588.049 nm) was found at X=0.6, pH 11 and sintering temperature of 850 °C. It was found that from the VSM graphs that magnetic saturation (Ms) has reached a maximum of 95 emu/g at X=0.6 pH 11, sintering temperature at 1050 °C and coercivity (Hc) at 0.13 T. Considering these properties, BaM was qualified as a candidate for stealth technology materials.