Abstract

Dy⁺³ doped strontium ferrites Sr_1-xDy_x (ZnZr)_0.5 Fe₁₁O₁₉ (x=0, 0.01, 0.02 and 0.03) were prepared by the citrate sol-gel method. The X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry, and vector network analyzer were used for phase characterization and microwave absorption properties of obtained powders. X-ray diffraction identified that all samples were single phase with the M-type hexagonal-ferrite structure. The average crystallite size was about 4862 nm. The microwave electromagnetic properties of the samples were studied at the frequency range from 12 GHz to 20 GHz. It was shown that small amounts of Dy⁺³ substitution could magically adjust to microwave electromagnetic parameters. The reflection loss indicates a minimum peak when ‘‘x=0.01’’, and the peak value was 41.0 dB. Also results indicate that a wide bandwidth of microwave absorption is obtained in the composite samples containing ferrite powders with composition ‘‘x=0.02’’ and ‘‘x=0.03’’ in Ku-band frequencies. It should be noted that thicknesses of the absorbers are only 1.7 mm.

Keywords: Chemical synthesis, nanostructures, magnetic properties, X-ray diffraction.