Effect of Ni2+ Substitution on the Structural, Magnetic, and Dielectric Properties of Barium Hexagonal Ferrites (BaFe12O19)

Polycrystalline barium hexaferrites BaFe12-xNixO19 (x = 0, 0.3 and 0.5) ceramics were synthesized by the conventional solid state route. X-ray diffraction and Fourier transform infrared spectroscopy studies confirmed the successful substitution of Ni in BaFe12O19 without the formation of any additional phase. Scanning electron microscopy images showed a platelet-like morphology of particles with an increase of average grain size by the increase in Ni content. A vibrating sample magnetometer revealed that the remnant magnetization M-r and coercivity H-c increased to a large extent, i.e., from 20.24 to 25.51 emu/g and from 1027.20 to 1971.60 Oe, respectively, with the increase in Ni from x = 0 to x = 0.5; however, saturation magnetization M-s showed a minor variation. Dielectric studies were done using a precision impedance analyzer, which showed a decrease in dielectric loss with the increase in Ni content and very little variation in the conductivity of the samples.