Microwave Absorption Properties of Fe-SiO<SUB>2</SUB> Nanocomposite Powder

Abstract

Nano-sized processing is reported to realize distinctive features in physical properties. We found a remarkable microwave absorption property caused by the increase of permeability and permittivity when nanocomposing ferromagnetic metals (Fe) and high electrical resistance ceramics (SiO2). The microwave absorption property was identified by comparing polymer composites containing Fe-SiO2 nanocomposite powder prepared by mechanical alloying and simple mixing of Fe-SiO2 powder in the frequency range of 0.1-18 GHz. We attributed these to the decrease in electrical conductivity and magnetostriction of Fe and improvement in the magnetic coupling between Fe grains.