In-situ combustion synthesis of Ni1-xZnxFe2O4/FeNi3/ZnO composite powders for electromagnetic absorption

The magnetic (Ni1-xZnxFe2O4/FeNi3 (x = 0.5 and 0.7))/dielectric (ZnO) composites were designed as microwave absorbers. The composite absorbers with uniform phase distribution were in-situ prepared by mixing the precursor solutions of Ni1-xZnxFe2O4 and ZnO in solution combustion method. To tune the dielectric and magnetic properties, the amount of crystallized ZnO phase varied in the range of 0-54 wt % as a function of fuel contents and composition (x). The composite containing amorphous ZnO phase showed high microwave absorption performance, including a minimum reflection loss of -40 dB and effective absorption bandwidth of 3.4, 4, 3.8, and 1.8 GHz in Ku, X, C2, and C1 bands at matching thicknesses of 2.2, 3, 4.2, and 6.5 mm, respectively.

Automated summary

The magnetic (Ni1-xZnxFe2O4/FeNi3 (x = 0.5 and 0.7))/dielectric (ZnO) composites were designed and in-situ prepared as microwave absorbers. By varying the fuel contents and composition (x), the crystallized ZnO phase in the composites was adjusted from 0 to 54 wt % to tune the dielectric and magnetic properties. The composite with amorphous ZnO phase exhibited excellent microwave absorption performance, with a minimum reflection loss of -40 dB and effective absorption bandwidth of 3.4, 4, 3.8, and 1.8 GHz in Ku, X, C2, and C1 bands at specific matching thicknesses.