| 摘要 |
PROBLEM TO BE SOLVED: To provide a composite magnetic material which can be used at high frequency up to a microwave range, and to provided a radio wave absorber using the same. SOLUTION: In the composite magnetic material in which magnetic fine particles are dispersed in a dispersion base, a magnetic fine particle has a structure consisting of a core-shaped magnetic layer and a nonmagnetic core. Consequently, by obtaining an effective permeability while keeping magnetic interactions between magnetic fine particles, reduction in weight is realized, and moreover, by constraining magnetization of the core-shaped magnetic layer to the core surface of the magnetic fine particle, a natural resonant frequency is heightened and a threshold frequency of permeability is shifted to a higher frequency, which enables to improve high frequency characteristics. Also, by giving the dielectric properties to the nonmagnetic part of the inside of the magnetic fine particle, the dielectric properties of the composite magnetic material can be controlled. |
