Size effect on the static and dynamic magnetic properties of W-type barium ferrite composites:: From microparticles to nanoparticles -: art. no. 094310

The static, dynamic, and attenuation properties of BaCoZnFe16O27 barium ferrites and their composites have been studied using microparticles and nanoparticles. The results showed that BaCoZnFe16O27 microparticles have larger saturation magnetization M-s and smaller coercivity H-c than do nanoparticles. The composites with microparticles have significantly larger real and imaginary permeabilities mu(')(0) and mu(')(max) due to their multidomain structures, but low resonance frequency f(R), 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. (c) 2005 American Institute of Physics.