Size effect on the static and dynamic magnetic properties of W -type barium ferrite composites: From microparticles to nanoparticles

Abstract

The static, dynamic, and attenuation properties of BaCoZn Fe16 O27 barium ferrites and their composites have been studied using microparticles and nanoparticles. The results showed that BaCoZn Fe16 O27 microparticles have larger saturation magnetization Ms and smaller coercivity Hc than do nanoparticles. The composites with microparticles have significantly larger real and imaginary permeabilities μ0′ and μmax″ due to their multidomain structures, but low resonance frequency fR, as compared with the composites with nanoparticles. The predicted dependence of the reflection loss on frequency showed that the composites with microparticles have much better attenuation for use as electromagnetic (EM) materials with low reflectivity and broad bandwidth at microwave frequency. © 2005 American Institute of Physics.