What does ferrimagnetism mean?
Ferrimagnetism is a form of magnetism found in certain materials in which neighboring atomic magnetic moments align in opposite directions but are of unequal strength, leaving a residual net magnetization. This distinguishes it from ferromagnetism, where all moments point the same way, and from antiferromagnetism, where equal and opposite moments cancel exactly. The phenomenon is characteristic of ferrites — ceramic compounds of iron oxides with other metals — and of magnetite (Fe₃O₄), the mineral behind the ancient lodestone. The concept was developed by French physicist Louis Néel in the late 1940s, work for which he later received the Nobel Prize in Physics. In practical terms, ferrimagnetic materials are valuable because they are electrically insulating yet strongly magnetic, making them essential in transformers, microwave devices, and early magnetic memory. Though strictly a scientific term, ferrimagnetism names one of nature's most consequential magnetic behaviors, underlying technologies from radio antennas to data storage.
nounA type of magnetism in which the atomic magnetic moments in a material align antiparallel but with unequal magnitudes, producing a net spontaneous magnetization. It is the magnetic behavior characteristic of ferrites and magnetite.
- The phenomenon in which unequal antiparallel alignment of atomic magnetic moments produces net spontaneous magnetization, as seen in ferrites such as magnetite.
"Ferrimagnetism explains why magnetite, the original lodestone, is strongly magnetic despite its opposing atomic moments."
"Louis Néel's theory of ferrimagnetism earned him a share of the 1970 Nobel Prize in Physics."
"Because of ferrimagnetism, ferrite cores can store magnetic states efficiently, making them useful in early computer memory."
Rarely if ever pluralized; the word is an uncountable mass noun denoting a physical phenomenon.
"Ferrimagnetism is studied extensively in condensed-matter physics."
Magnetite was humanity's first magnet — and ferrimagnetism, not ferromagnetism, is what makes it magnetic at all.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of ferrimagnetism
The word ferrimagnetism combines Latin ferrum, meaning 'iron', with 'magnetism', which traces back through Latin magnes to Greek magnētis lithos, the 'Magnesian stone' or lodestone, named after Magnesia in Asia Minor. The term was coined by French physicist Louis Néel in 1948 to describe the intermediate magnetic behavior he had theorized between ferro- and antiferromagnetism. It shares its iron-derived root with related scientific terms such as ferrous, ferrite, and ferromagnetism, all pointing to the central role of iron in magnetism.
Related word forms
How ferrimagnetism is actually used
A technical term used almost exclusively in physics, materials science, and engineering contexts; it carries no figurative or informal use. The term was introduced by Louis Néel in 1948.
Easily confused with ferrimagnetism
In ferromagnetism all atomic moments align parallel in the same direction, whereas in ferrimagnetism they align antiparallel but unequally, leaving only a partial net magnetization.
Antiferromagnetism involves equal antiparallel moments that cancel completely, so there is no net magnetization, unlike ferrimagnetism where unequal moments leave a net field.