ferriiti

Ferriiti, commonly known in English as ferrite, is a class of ceramic iron oxide–based compounds that adopt a spinel crystal structure. Their general chemical formula is MFe2O4, where M represents a divalent metal such as Zn, Ni, Mn, Mg, Co, or Cu. In the spinel lattice, oxide ions form a close-packed framework with metal cations occupying tetrahedral and octahedral sites; the distribution of M and iron between these sites governs the material’s magnetic and electrical properties.

Ferritiit are ferrimagnetic materials, meaning the magnetic moments of the sublattices align oppositely but do not cancel completely, giving a net magnetization. Common ferritiit include zinc ferrite (ZnFe2O4), nickel ferrite (NiFe2O4), manganese ferrite (MnFe2O4), and magnesium ferrite (MgFe2O4). Magnetite (Fe3O4) is a naturally occurring ferrite-like oxide with a spinel structure and is often cited as a prototype ferrite.

Ferriiti can be divided into soft ferrites, which have low coercivity and are optimized for high-frequency transformer cores and inductors, and hard ferrites, such as barium ferrite (BaFe12O19) and strontium ferrite (SrFe12O19), used in permanent magnets and magnetic recording media. Synthesis methods range from conventional solid-state reactions to chemical routes like co-precipitation and sol-gel processing; processing temperature, particle size, and microstructure strongly affect magnetic behavior.

Ferriiti are valued for their electrical resistivity, thermal stability, chemical inertness, and relatively low cost, making them essential in electronics, energy, and catalysis.