Structural Characteristics of Spinel Ferrites
Crystal System and General Formula: Belongs to the face-centered cubic (fcc) structure; the general chemical formula is MFe₂O₄ (where M represents a divalent metal ion, such as Mn, Zn, or Ni).
Ion Site Distribution: Divalent metal ions (A-sites) and trivalent Fe ions (B-sites) occupy distinct lattice positions; only the inverse spinel structure exhibits macroscopic magnetic properties, whereas the normal spinel structure is non-magnetic.
Performance Suitability:Characterized by high magnetic permeability and low coercivity, this is the dominant structure for soft ferrites, suitable for applications ranging from audio frequencies to the very-high-frequency (VHF) range.
Structural Characteristics of Magnetoplumbite Ferrites
Crystal System and General Formula: Primarily hexagonal crystal system; the general chemical formula is MFe₁₂O₁₉ (where M represents a divalent metal ion, such as Ba or Sr).
Key Structural Features: Exhibits strong magnetocrystalline anisotropy and high lattice stability; coercivity is significantly higher than that of the spinel structure.
Performance Suitability: Represents the typical structure for hard (permanent magnet) ferrites; chemically stable and widely used in permanent magnet devices.
