Ferrimagnetism

Ferrimagnetism is magnetic order in which oppositely aligned moments have unequal magnitudes, leaving a nonzero net magnetization. It commonly occurs in compounds with distinct magnetic sublattices.

Magnetic sublattice: A group of magnetically equivalent atomic sites within an ordered material. Ferrimagnets contain sublattices whose opposing moments differ in total magnitude.
Antiferromagnetism: Magnetic order in which neighboring moments align oppositely and cancel to give zero net magnetization. Ferrimagnetism also has antiparallel moments, but their unequal magnitudes prevent complete cancellation.
Ferrite: A ceramic material composed mainly of iron oxide combined with other metal oxides. Ferrites are widespread ferrimagnets used in electrical and magnetic components.
Magnetite: A naturally occurring iron oxide, Fe₃O₄, with a cubic inverse-spinel structure. Magnetite is a classic ferrimagnet with unequal iron-ion sublattice moments.
All-optical switching: Magnetization reversal driven by light without an applied magnetic field. Ferrimagnetic alloys can reverse rapidly under laser pulses through unequal sublattice dynamics.
Exchange interaction: A quantum-mechanical interaction that favors particular relative orientations of neighboring spins. Exchange interactions establish the antiparallel alignment between ferrimagnetic sublattices.
Ferromagnetism: Magnetic order in which moments align parallel, producing spontaneous net magnetization. Unlike ferrimagnets, ferromagnets do not rely on opposing sublattices for net magnetization.
Magnetic recording: Data storage that represents information through magnetic states in a recording medium. Ferrimagnetic films and particles have served as recording media and readout components.
Maghemite: A ferrimagnetic iron oxide, γ-Fe₂O₃, related structurally to magnetite but containing vacancies. Its structure and nanoscale forms make it a common ferrimagnetic comparison to magnetite.
Compensation temperature: A temperature at which opposing magnetic sublattice contributions cancel in a ferrimagnet. Controlling compensation conditions may enable faster switching and reduced magnetic-field requirements.

Linked from 13 pages