Magnetic and Microwave Absorbing Properties of Ti - and Co - Substituted Barium Ferrite (BaFe12-2XTiXCoXO19)

The M-type barium ferrite (BaFe₁₂O_(19)) is well known magnetic material to be used as a permanent magnet due to its strong uniaxial anisotropy. The substitution of nonmagnetic Ti+⁴ and magnetically weak Co+² ion for Fe+³ sublattices reduces the uniaxial anisotropy and those compounds open a new application field of noise suppressor at high frequencies. In this study, the magnetic and microwave absorbing properties are investigated in Ti and Co- substituted barium ferrites (BaFe_(12-2X)Ti_XCo_XO_(19)). The saturated magnetization decreases linearly with the substitution of Ti and Co. The rapid drop in coercive force is observed with Ti and Co substitution upto x=1.2. The magnetic permeability spectrum shows the natural magnetic resonance in the specimens with small coercive force and large attenuation of microwave is predicted in those specimens at high frequencies (above 4㎓).