Fabrication and elucidation of electromagnetic characteristics in Cr–Zn co-substituted strontium hexaferrite for high-frequency device applications

The paper describes the effect of Cr–Zn substitution in Sr1−xCrxFe12−yZnyO19 (0 ≤ x ≤ 0.8; 0 ≤ y ≤ 1) hexaferrite, synthesized by the sol–gel auto-combustion method. The prepared samples are examined with XRD and FTIR to ensure the successful formation of the magnetoplumbite hexagonal structure. The magnetic study suggests that the magnetic tunability characteristic of strontium hexaferrite may be utilized to expand the application area from hard to soft magnet applications. The substitution of the Cr3+ ion at Sr site improves the coercivity of the material; however, substituting the Zn2+ ion at Fe site increases the saturation magnetization. A very high value of saturation magnetization, ~ 78 emu/g, is obtained for SrFe11ZnO19 composition with a small coercivity of ~ 64 Oe. A dielectric resonator antenna model is simulated in Ku-band for the proposed application. The obtained results positively suggest the exploration of strontium hexaferrite-based magnets in antenna applications at higher frequencies.