Structural, magnetic, and microwave properties of NdZn-substituted Ca_0.5Ba_0.5Fe₁₂O₁₉ hexaferrites

Substitution of NdZn in Ca_0.5Ba_0.5−x Nd _x Zn _y Fe_12−y O₁₉, (x = 0.00–0.10; y = 0.00–1.00) hexaferrites prepared by sol–gel method is investigated, and their effect on the microwave, structural, and magnetic properties is reported. The XRD patterns reveal single-phase M-type hexaferrite structure. The lattice parameters were found to increase by the substitution of NdZn. The increase in lattice parameters is due to the difference in ionic sizes of the cations involved. The average grain size was found between 16 and 29 nm by Scherer formula and was also confirmed by SEM and TEM. Magnetic behavior of selected sample was observed up to a magnetic field of 8T taken at temperature ranges from 4.2 to 373 K. The coercivity of the sample decreased from 2300 to 1210 Oe with increasing temperatures in a linear fashion up to 373 K. The grain boundaries, and the associated pinning fields, seem to have a resolute role in the magnetic behavior of these hexaferrites. Microwave measurements of the ferrite sample have been measured in the frequency range 0.5–12 GHz. The frequency dispersion of ferrites is credited to the phenomenon of natural magnetic resonance and domain wall pinning.