Optimization of structural, morphology, site occupancy, and hysteresis performance metrics of Co-Cd Co-doped SrM hexaferrite for recording applications

In the current work, a sol-gel combustion technique has been adopted to synthesize Co-Cd substituted SrM hexaferrite. The X-ray patterns of incorporated samples showed the magnetoplumbite structure, accompanied by some secondary phases of CoFe2O4. The morphological studies of the z = 0.6, 0.8, and 1.0 revealed the densification of grains, which enhances the inter-particle contact. The energy dispersive spectra exhibited peaks of cadmium, cobalt, strontium, oxygen, and ferrite, signifying the formation of Co-Cd substituted SrM hexaferrite. Mössbauer spectra revealed that the substituent tends to occupy spin-down sites 4f1 and 4f2 of the crystal lattice from z = 0.2 to 0.6, elucidating a significant increase in saturation magnetization. A large value of coercivity 4273.50 Oe, 3612.63 Oe, and 4551.28 Oe was observed for z = 0.4, 0.6, and 1.0 samples, respectively, with a squareness ratio greater than 0.5, indicating the existence of single-domain particles. The high values of saturation and remanent magnetization with tunable coercivity and squareness ratio make the prepared sample suitable for recording applications.