The influence of Bi-Co doping on structural, morphological, dielectric and magnetic properties of Ca1-xBixFe12-xCoxO19

The sol-gel auto-combustion method was employed to synthesize Ca1-xBixFe12-xCoxO19 M-type hexaferrites. X-ray diffraction (XRD) analysis confirmed the formation of a single phase M-type hexagonal structure, with a crystallite size ranging from 23.51 to 23.08 nm. The doping contents were found to decrease the bulk and X-ray densities while increasing the porosity. Fourier-transform infrared (FTIR) spectra showed the formation of metaloxygen stretching vibrations that confirmed the hexagonal ferrites. The scanning electron microscopy (SEM) images revealed a regular platelet hexagonal structure with homogeneously distributed grains. The dielectric constant was high at low frequency and decreased with increasing frequency, while the dielectric loss decreased appreciably with doping. The saturation magnetization ranged from 38.27 to 15.51 emu/g, coercivity increased from 207.93 to 1359.69 Oe, and the squareness ratio was in the range of 0.19-0.78. All synthesized samples exhibited greater coercivity values than Mr/2, indicating their hard nature and potential use in high frequency applications.

Automated summary

The sol-gel auto-combustion method was used to synthesize Ca1-xBixFe12-xCoxO19 M-type hexaferrites. The synthesized hexaferrites exhibited a single phase M-type hexagonal structure with a crystallite size of 23.51-23.08 nm. Doping led to decreased bulk and X-ray densities, but increased porosity. The synthesized hexaferrites showed good potential for high frequency applications due to their high coercivity values and hard nature.