What does diamagnetic mean?
Diamagnetic describes the weakest and most universal form of magnetism found in matter. A diamagnetic material — examples include water, copper, graphite, and bismuth — develops an induced magnetic moment opposite to whatever external magnetic field it experiences, with the result that it is very slightly repelled by both poles of a magnet. This contrasts sharply with ferromagnetic substances like iron, which are strongly attracted to magnets, and with paramagnetic materials, which are weakly attracted. Because all atoms exhibit some diamagnetic response, the effect exists everywhere but is usually masked by stronger magnetic behavior; only in substances where those effects are absent does diamagnetism become observable. In practice the word appears almost entirely in physics and chemistry contexts, as in 'a diamagnetic susceptibility measurement' or 'bismuth is strongly diamagnetic.' It also underpins striking demonstrations of diamagnetic levitation, in which small objects float above powerful magnets.
adjectiveRelating to or exhibiting diamagnetism: the property of being very weakly repelled by a magnetic field, in contrast to paramagnetic and ferromagnetic materials. Diamagnetic substances acquire an induced magnetic moment opposite in direction to the applied field.
- (Physics) Having the property of being weakly repelled by a magnetic field; of or relating to diamagnetism.
"A diamagnetic material such as bismuth is feebly repelled by either pole of a strong magnet."
"Water, though we rarely think of it this way, is a diamagnetic substance and can be made to levitate in a sufficiently strong field."
"The researchers used a diamagnetic trap to hold the sample steady without any physical contact."
Diamagnetic levitation is real: scientists have floated frogs — and even briefly levitated living mice — inside powerful magnets, because every atom carries a trace of diamagnetic repulsion.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of diamagnetic
Diamagnetic was coined in the nineteenth century from the Greek-derived prefix dia- (meaning 'through' or 'across') combined with magnetic, which itself traces back through Latin magneticus to Greek magnētis lithos, 'stone of Magnesia,' a region of Thessaly associated with lodestones. The related noun diamagnetism and the term diamagnet arose alongside it as physicists classified matter by its response to magnetic fields. The word shares its ultimate root with other magnet- derivatives such as magnetize, magnetism, and electromagnetic.
Related word forms
How diamagnetic is actually used
A technical term used chiefly in physics and materials science; it appears mainly in formal, academic, or popular-science writing rather than everyday speech.
Easily confused with diamagnetic
Paramagnetic materials are weakly attracted to a magnetic field, whereas diamagnetic materials are weakly repelled by it.