What does ferromagnet mean?
A ferromagnet is a material — most famously iron, along with nickel and cobalt — that exhibits ferromagnetism, the strongest form of everyday magnetism. In these substances, the magnetic moments of neighbouring atoms align parallel to one another within regions called domains, allowing the material to be strongly magnetized and, in some cases, to remain permanently magnetic once the external field is removed. Physicists further distinguish soft ferromagnets, which magnetize and demagnetize readily and are prized in transformer cores, from hard ferromagnets, which hold their magnetization and serve as permanent magnets. The term belongs mainly to physics and materials science, where precision matters: ordinary speakers simply say 'magnet'. Notably, ferromagnetism is temperature-sensitive — heated above its Curie point, a ferromagnet loses its spontaneous alignment and reverts to weak paramagnetism, a dramatic phase transition first explained by Pierre Curie's work in the nineteenth century.
nounA ferromagnet is a material or object that exhibits ferromagnetism — that is, a substance capable of spontaneous, strong magnetization in which the magnetic moments of its atoms align parallel to one another, such as iron, nickel, or cobalt.
- A substance, such as iron, nickel, or cobalt, whose atomic magnetic moments align spontaneously so that it can be strongly magnetized or act as a magnet.
- (Physics, more broadly) Any body or device component made from such a ferromagnetic material, as used in transformer cores and permanent magnets.
"The compass needle swung because the lodestone at its heart was a natural ferromagnet."
"In a transformer core, engineers choose a soft ferromagnet that magnetizes and demagnetizes easily with alternating current."
"Because the alloy remained a ferromagnet at high temperatures, it was ideal for the motor's permanent magnets."
Regular plural; standard in technical writing when discussing classes of magnetic materials.
"Hard ferromagnets such as alnico alloys are used to make permanent magnets."
Strip a ferromagnet past a critical temperature called the Curie point and it abruptly forgets it was ever magnetic — heat iron above 770°C and its magnetism vanishes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of ferromagnet
The word ferromagnet combines 'ferro-', from the Latin ferrum meaning 'iron', with 'magnet', which traces back through Latin magnes to Greek magnētis lithos, literally 'stone of Magnesia', referring to the naturally magnetic lodestone found near Magnesia in Asia Minor. The compound arose in the late nineteenth century alongside the scientific term ferromagnetism, coined to distinguish iron-like magnetism from weaker dia- and paramagnetic behaviour as physicists systematically classified magnetic materials.
Related word forms
How ferromagnet is actually used
Ferromagnet is primarily a technical term used in physics, materials science, and electrical engineering; in everyday speech people usually just say 'magnet' or name the metal itself. The word refers to the material or body, while 'ferromagnetism' names the phenomenon and 'ferromagnetic' is the adjective form. Classifying a material as a ferromagnet depends on temperature: above its Curie point, a ferromagnet becomes merely paramagnetic.
Easily confused with ferromagnet
A paramagnet is only weakly and temporarily attracted by an external magnetic field, whereas a ferromagnet retains strong magnetization even without an external field.
A diamagnet is weakly repelled by magnetic fields, the opposite behaviour of a strongly attracted ferromagnet.