5. Comparison of Mn-Zn spinel ferrites with nanocrystalline soft metal alloys

We have already explained that metallic magnetic materials are penalized by their low electrical resistivity for high-frequency applications. For this reason, the designer must forego the use of conventional iron-silicon or iron-nickel laminations for frequencies above around 10 kHz. Nevertheless, the effects of induced currents can be countered by reducing the thickness of the metal alloy. Today, manufacturers are able to synthesize amorphous or nanocrystalline [E 1 770] ribbons some twenty micrometers thick. These ribbons can be used to manufacture "wound" cores, which can then be used to make inductors or transformers. The resulting components have very interesting properties in the mid-frequency range.

To clarify the frequency range at which it is preferable to use one type of...