Structure and Electromagnetic Properties of Nanocrystalline Sr1-xDyx(ZnZr)0.5 Fe11O19

Dy+3 doped strontium ferrites Sr1-Dyx (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 48-62 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.