Relationship between Residual Loss and Microstructure of Mn-Zn Ferrites

The core loss characteristics of the Mn-Zn ferrite cores with various grain sizes, electric conductivities and cross sectional areas are analyzed. A part of the residual loss depends on the grain size. It is 4 orders of magnitude larger than the intragrain eddy current loss estimated classically. On the other hand, the core loss calculated by using the dynamic magnetic loss parameter recently introduced by Saotome and Sakaki includes the part. This indicates that the part of the residual loss is related to the interaction between the applied field and the induced magnetic flux.