Enhanced microwave absorption properties of Zn-substituted SrW-type hexaferrite composites in the Ku-band

Enhanced microwave absorption properties were successfully achievable from SrFe2-xZnxFe16O27 (SrFe2-xZnxW; x = 0.0, 0.5, 1.0, and 2.0) hexaferrite filler-epoxy resin matrix composites. The composite samples were fabricated with the filler volume fractions (V-f) of 30, 50, 70, and 90%. Compared with fully Zn-substituted SrZn2W composite (x = 2.0), unsubstituted and partially Zn-substituted SrFe2-xZnxW (x = 0.0, 0.5, and 1.0) composites exhibited much higher real and imaginary parts of complex permittivity (epsilon(r)), which is attributable to higher electron hopping between Fe2+ and Fe3+ ions, and also slightly higher real and imaginary parts of complex permeability (mu(r)) due to higher saturation magnetization (M-s). Among all samples, a 2.8 mm-thick SrFe1.5Zn0.5W (x = 0.5) composite with the V-f of 90% exhibited the most appropriate for application in the region of 3.4-3.8 GHz, having the minimum reflection loss (RLmin) of -46 dB at 3.6 GHz with the bandwidth of 0.43 GHz (3.38-3.81 GHz) below -10 dB, while a 2.15 mm-thick SrFeZnW (x = 1.0) composite with the V-f of 70% showed the most appropriate for application in the region of 5.9-7.1 GHz, possessing the RLmin value of -23.7 dB at 6.6 GHz with the bandwidth of 1.38 GHz (5.85-7.23 GHz) below -10 dB. Consequently, partially Zn-substituted SrW-type hexaferrites are very promising microwave absorbers for 5G mobile communications in the Ku band (0.5-18 GHz).

Automated summary

Enhanced microwave absorption properties were achieved in SrFe2-xZnxF hexaferrite filler-epoxy resin matrix composites. Partially Zn-substituted composites showed the best performance in the 3.4-3.8 GHz and 5.9-7.1 GHz ranges.