DC Bias Effect on the Magnetic Properties in NiZn Ferrite

Abstract

Magnetic properties of mono-domain and multi-domain NiZn ferrites under dc magnetic flux densities were investigated with regard to actual performance in power circuits. Bias properties were measured along the initial magnetization curve. The magnetizing process in the multi-domain sample is mainly dominated by domain-wall motion even in the low ac magnetic flux density region. In contrast, in the mono-domain sample, magnetization is reversible and core loss is low regardless of the dc magnetic flux density because the spin rotation dominates if ac flux density is below 20 mT.