MnZn-doped W-type barium cobalt ferrite powder composites of Ba(MnZn) x Co 2(1-x) Fe 16 O 27 (x = 0.1, 0.2, 0.3, 0.4, and 0.5) were prepared in a sol-gel process. The microwave absorbing properties of the composites in the range of 2 - 18 GHz and their electromagnetic loss mechanisms were studied. The results demonstrated that the synthesized Ba(MnZn) x Co 2(1-x) Fe 16 O 27 samples possess a W-type phase of the crystal structure with a hexagonal flaky shape in micro-morphology, and the samples exhibited a soft magnetic trait that enables improving their microwave absorption properties through suitable MnZn doping. For Ba(MnZn) 0.4 Co 1.2 Fe 16 O 27 with a thickness of 2.8 mm , the reflection loss peak was -40.7 dB at a frequency of 7.3 GHz, with a bandwidth of 6.6 GHz at a loss of less than -10 dB. The microwave absorption primarily resulted from magnetic losses caused by magnetization relaxation, domain wall resonance, and natural resonance.
KeywordsSol-Gel ProcessW-Type FerriteMicrowave Absorbing MaterialsElectromagnetic Loss
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