Influence of microstructure on properties of Ni–Zn ferrite radio-absorbing materials

•Addition of Bi2O3 up to 1 mass% leads to increasing grain sizes of Ni-Zn ferrites.•Coarse-grained structure is achieved adding ferrite particles of a large fraction.•Coarse-grained structure leads to increasing absorbing capacity at low frequencies.•It can be explained by the resonance of domain boundaries.

In this work there have been carried out studies in the radiophysical characteristics of the samples of Ni–Zn ferrite radio-absorbing materials, obtained by the ceramic method under different technological conditions. There has been established the influence of microstructure on the electromagnetic losses of Ni–Zn ferrite radio-absorbing materials. The results indicate that the coarse-grained structure leads to an increase of radio-absorbing capacity at frequencies below 30 MHz. It can be explained by the resonance of domain boundaries.