Which metal ions are commonly used in spinel ferrites?

In the context of magnetic ceramics, spinel ferrites are crystalline minerals with the general chemical formula $M(F{e}_2{O}_4)$. In this structure, the metal cation $M$ is typically a divalent ion, such as:

• Manganese ($M{n}^{2+}$)
• Nickel ($N{i}^{2+}$)
• Cobalt ($C{o}^{2+}$)
• Zinc ($Z{n}^{2+}$)
• Copper ($C{u}^{2+}$)
• Magnesium ($M{g}^{2+}$)

Additionally, $M$ can represent the monovalent lithium cation ($L{i}^{+}$) or even vacancies, provided that the absence of positive charge is compensated for by additional trivalent iron cations ($F{e}^{3+}$). These materials are valued for their soft magnetic properties, high electrical resistivity, and high relative permeability, making them particularly useful in high-frequency electronic equipment.12