Why do magnetic ceramics have lower saturation magnetization than magnetic metals?

Magnetic ceramics, known as ferrites, exhibit lower saturation magnetization than magnetic metals because of the fundamental difference in how their atomic magnetic moments align.

While magnetic metals like iron, cobalt, and nickel exhibit ferromagnetism, where all unpaired electron spins within a domain align in the same direction, magnetic ceramics exhibit ferrimagnetism. In ferrites, the crystal structure contains multiple types of lattice sites, and the electron spins align in opposing directions—some "spin-up" and others "spin-down".12

This antiparallel alignment leads to an incomplete cancellation of the magnetic moments, resulting in a net polarization that is weaker than the total alignment found in ferromagnetic metals. This asymmetry in atomic orientation, caused by the complex crystalline structure and the presence of different types of magnetic ions, is the primary reason for their lower saturation magnetization.12