Abstract

In order to increase the magnetic loss for electromagnetic(EM) wave absorption, the soft magnetic Fe_73Si_16B_7Nb_3Cu_1(at%) alloy strip was used as the basic material in this study. The melt-spun strip was pulverized using an attrition mill, and the pulverized flake-shaped powder was crystallized at 540°C for 1h to obtain the optimum grain size. The Fe-based powder was mixed with 2 wt% BaTiO_3, 0.3sim0.6 wt% carbon black, and polymer-based binders for the improvement of electromagnetic wave absorption properties. The mixture powders were tape-cast and dried to form the absorption sheets. After drying at 100°C for 1h, the sheets of 0.5 mm in thickness were made by rolling at 60°C, and cut into toroidal shape to measure the absorption properties of samples. The characteristics including permittivity, permeability and power loss were measured using a Network Analyzer(N5230A). Consequently, the properties of electromagnetic wave absorber were improved with the addition of both BaTiO_3 and carbon black powder, which was caused by the increased dielectric loss of the additive powders.

• Keywords: Nanocrystalline;Permittivity;Permeability;Carbon black;BaTiO_3;Electromagnetic wave absorber;