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.