A composite consisting of flake-shaped Fe74Cr2Mo2Sn2P10Si4B4C2 particles was prepared.The flake-shaped particles included in the composite were prepared by planetary ball milling.The complex permeability of the composite material was measured at frequency range from 10 MHz to 8.5 GHz.The permeability of the composite containing flake-shaped particles was much higher than that of the spherical particles.The permeability of particles was improved by means of heat-treatment.In contrast to the random-spatial-distributed flake-shaped particle composites,the oriented-distributed ones had a higher effective permeability.A model was proposed considering the orientation ratio,and our calculation agreed well with the experimental data.
LIU KaiHuang1,LIU TianCheng1,2,LI JianLiang1,2,ZHANG Liang1,2,ZHANG HongHao1,2,LI DeRen1,2,LU ZhiChao1,2 & ZHOU ShaoXiong1,2 1 China Iron and Steel Research Institute,Beijing 100081,China
The noise suppression effect and its mechanism are investigated for a composite sheet and a composite film made of glass-covered amorphous CoFeSiBCr wires.Both samples show a significant noise suppression effect.The power loss ratio of the composite sheet is above 80% from 1.6 GHz to 8.5 GHz,and that of the composite film is above 70% from 3.2 GHz to 8.5 GHz even if its thickness is only 0.20 mm.The composite sheet demonstrates high real and imaginary permittivity above 30.7 and low real and imaginary permeability below 1.2.The surface resistivities of the two composite samples are as high as about 3 × 10^(12) Ω/square.The power loss of the composite containing glass-covered wires should be mainly contributed by dielectric loss derived from electronic polarization and relaxation.
