Microwave permittivity and permeability properties and microwave reflections of micro/nano ferrite powders

The application of magnetic powders are becoming attractive in electromagnetic shielding interferences in wireless systems. Magnetic powders such as Fe₃O₄ are also very important in magnetic resonance imaging as well as drug delivery applications in biomedical researches. Also, some of the special catalyst nano magnetic particles are increasingly useful in the fuel cell applications. Hence, a good understanding of the electromagnetic wave response such as permittivity and permeability of magnetic powders may be important in modern microwave technological applications. In this paper we present broad-band measurements on the real and imaginary parts of permeability and permittivity of micron sized commercial nickel ferrites of Ni_1-x-yCo_xCu_yFe_2-z-dMn_zO₄ (TT2) and Ni_1-xZn_xFe_2-yMn_yO₄ (TT86) in the frequency range from 4 to 40 GHz. We also present broadband permeability and permittivity of some other commercially available nano and micron sized ferrite powders, so that this is a paper that explores microwave properties of nine different nano and micron sized magnetic powders in terms of permittivity and permeability aspects.