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Intrinsic permeability of sendust alloys is determined from the measured microwave permittivity and permeability of composites filled with either spherical or flaky sendust powders. The permittivity and permeability measurements are performed applying the coaxial reflection-transmission technique in the 0.05 to 18 GHz frequency range. The effects of the filling factor, inclusion shape, and size on composite constitutive parameters are discussed. The permeability of metal inclusion is retrieved from the measured permeability of composites using a generalized Maxwell Garnett equation that accounts for the percolation threshold. The equation parameters are found by fitting the measured dependence of composite permittivity and permeability on frequency and filling. The inclusion dimensions calculated from the found parameters agree with the results of grain-size analyses. The alloy intrinsic permeability is retrieved from inclusion permeability with the account for skinning. The fitted frequency and damping factor of ferromagnetic resonance depend on the inclusion shape. The calculated reflectivity map of the flake-filled composite shows that sendust powders are promising fillers for interference suppressors and microwave absorbers at frequencies close to 1 GHz.

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Magnetic sedimentation processes near ferromagnetic wire were applied for the cellular and the biotechnological monitoring. Numerous biological applications ofmagnetic sedimentation, or high gradient magnetic separation (HGMS), achieved mainly for human blood cells, have shown that it is possible to distinguish between the diamagnetic Fe-zerospin oxidized states and the paramagnetic Fe-high-spin reduced ones in red blood cells. The precision methods of the measurements ofcapture travelling (magnetic diffusion) time or accumulation (magnetic sedimentation) radius in HGMS have shown that it is really to determine the weak dia-or paramagnetic shifts ofmagnetic susceptibility up to 0.7 10'°(SI). The capture and sedimentation ofparticles with 5-40 .tm sizes on single magnetized wires were investigated using microscopic video-recording type. Magnetic susceptibility bars for cells in normal and disturbed states demonsrated the high reproducibility and narrow distribution patterns.

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