Physical properties of ferrites
Soft ferrites for power electronics

Ferrites are ionic compounds whose main constituents are trivalent iron and oxygen. Soft ferrites used for their high permeability and/or low losses have a spinel-type cubic crystallographic structure, similar to that of MgAl₂O₄ spinel.

The chemical formulae of spinel-structured ferrites are written MeFe₂O₄. In the simplest structure, Me represents a divalent metal cation, with iron in a trivalent state. The most interesting ferrites for applications are complex, in which case Me represents a combination of divalent ions (Mn²⁺, Ni²⁺, Zn²⁺, Fe²⁺, Co²⁺, Cu²⁺...), as well as combinations of monovalent (Li⁺), trivalent...