Ferrites
The productgroup Ferrites comprises the following: Ferritebeads, Ferritecores and EMI-Filters.
Ferrites are chemical compounds consisting of ceramic materials with iron (Fe2O3) as their principal component. Many of them are magnetic materials and they are used to make permanent magnets, ferrite cores for transformers, and in various other applications.
Ferrites are usually non-conductive ferrimagnetic ceramic compounds derived from iron oxides such as hematite (Fe2O3) or magnetite (Fe3O4) as well as oxides of other metals.
Ferrites are, like most other ceramics, hard and brittle. In terms of their magnetic properties, the different ferrites are often classified as “soft” or “hard”, which refers to their low or high magnetic coercitivity.
Soft Ferrites
Ferrites that are used in transformer or electromagnetic cores contain nickel, zinc and/or manganese compounds. They have a low coercitivity and are called soft ferrites. The low coercivity means the material’s magnetization can easily reverse direction without dissipating much energy (hysteresis losses), while the material’s high resistivity prevents eddy currents in the core, another source of energy loss. Because of their comparatively low losses at high frequencies, they are extensively used in the cores of RF transformers and inductors in applications such as switched-mode power supplies.
The most common soft ferrites are Manganese-zinc ferrites and Nickel-zinc for frequencies above 1 MHz.
