Coexistence of Zn and Fe ions influenced magnetic and microwave shielding properties of Zn-doped SrFe12O19 ferrites

We present the structural characterization, valence change of Fe, Raman spectra, and magnetic and microwave shielding properties of polycrystalline SrFe12-xZnxO19 (x = 0-1) samples. X-ray diffraction and Raman analyses indicated the samples having the M-type hexaferrite structure. The Zn doping caused a remarkable change in the lattice constants. Investigating magnetic hysteresis loops, we found an enhanced saturation magnetization (M-s) as increasing x from 0 to 0.1, and a reduced M-s as x > 0.1. Nearly the same tendency was also observed for the coercive force. Such changes have been thought to the Zn substitution and the valence change of Fe, as affirmed from analyzing the X-ray absorption data. Considering the shielding properties, we observed the samples with a thickness of 1.8 mm showing a low reflection loss. Among the investigated samples, the sample with x = 0.4 had the lowest reflection loss of about -20 dB at frequency of 11.7 GHz, corresponding to similar to 99% microwave energy being absorbed. We have considered that both dielectric and magnetic losses contribute to the microwave-absorption properties of SrFe12-xZnxO19.

Automated summary

The study focuses on the structural characterization, valence change of Fe, Raman spectra, and magnetic and microwave shielding properties of polycrystalline SrFe12-xZnxO19 (x = 0-1) samples. The Zn doping caused notable changes in the lattice constants, saturation magnetization, and coercive force of the samples. Additionally, the analysis revealed that both dielectric and magnetic losses contribute to the microwave-absorption properties of SrFe12-xZnxO19.