Microwave Absorption Characteristics of U-Type Ferrite Powders According to Substitution Elements and Its Compositions

In this study, partially substituted U-type ferrite (Ba 4 Me x Co 2-x Fe 36 O 60 , Me: Mn, Ni, Zn, x = 0.5 and 1.0) powders were synthesized by sol–gel method. The powders were analyzed for phase formation, morphology and magnetic properties by XRD, FE-SEM and VSM respectively. The synthesized ferrite powders were pressed into a series of toroidal shaped samples, in which the weight ratio of paraffin to powder was 1:5. The complex scattering parameters were measured by using vector network analyzer in the frequency range of 2–18 GHz and were employed in the calculation of reflection loss with various thicknesses. The minimum reflection loss was observed in the substituted nickel sample as − 24.4 dB (absorption rate 99.6%) with a thickness of 2.5 mm and the bandwidth was achieved 4.8 GHz (from 7.5 to 12.3 GHz) for reflection loss ≤ − 10 dB in the substituted zinc sample. Graphic Abstract