Microwave properties of FeCo–SiO2 systems obtained by high-energy milling

Resumo

Structural and phase composition and magnetostatic and microwave properties of Fe₇₀Co₃₀–SiO₂ systems obtained by high-energy milling in acetone for different times (from 6 to 48 h) are studied. It is found that, after the longest milling time, the obtained particles have sizes from 0.5 to 5 μm, are covered with a thin layer of SiO₂, and contain 10 wt % iron carbides. Milling-induced change in the phase composition of the particles influences their specific magnetization of saturation and coercive force, but has a small effect on the microwave permittivity of composite materials containing these particles in the frequency range of 0.1–6 GHz. As the milling time grows, the imaginary part of the microwave permeability decreases at frequencies below 1 GHz.