| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1800867 | Journal of Magnetism and Magnetic Materials | 2011 | 6 Pages |
Metal nanopowder (Co and Fe)/polymer composites, both with and without surface modification by behenic acid, were fabricated and their dielectric and magnetic properties were measured at 1 GHz to study the effect of surface modification on the electromagnetic properties. The relative permittivity and the real part of the permeability of the composites with surface modified powders were higher than those with unmodified powders. Related dielectric losses remained at almost the same level, but magnetic losses were somewhat increased. The increase of relative permittivity could result from the increased volume fraction of interphase with a slightly higher relative permittivity at the particle/polymer interface than that of the bulk polymer. The increase in the real part of the permeability may be caused by suppression of the induced demagnetizing field due to suppression of eddy currents by a better particle distribution and a decrease in effective agglomerate size because of the surface modification.
► Metal/polymer composites from surface modified nano Co and Fe powders. ► We evaluated their electromagnetic properties at 1 GHz. ► The surface modification raised both ε′ and μ′. ► Especially, ε′ of nano-Fe composite was raised from 5.5 to 14 at ca. 15 vol.%. ► Particle dispersion, distribution and interphase play important roles in the effect.
