Electromagnetic wave absorbing properties of Fe73Si16B7Nb3Cu1 base P/M sheets mixed with dielectric fine particles

Fe-based nanocrystalline powder sheets with dielectric TiO2 powder additives were investigated to improve the characteristics of electromagnetic (EM) wave absorption. The amorphous ribbons of Fe73Si16B7Nb3Cu1 (at.%) alloys were prepared by a planar flow casting (PFC) process, and the ribbons were pulverized using an attrition mill. Fe-based flake powder crystallized at 550°C for 1h was mixed with a nano-sized and a micro-sized TiO2 powder. The powder mixtures were then tape-cast with binders to become EM wave-absorbing sheets. The absorbing properties of the fabricated sheet sample, such as complex permittivity and permeability, were measured by a network analyzer. The properties of EM wave absorption improved with the increase of TiO2 powder in the mixture. The mixture with micro-sized TiO2 powder was a little more effective in causing power loss of EM waves than the mixture with nano-sized TiO2 powder.