Diamagnetism

Article By:

Abrahams, Elihu Department of Physics and Astronomy, University of California, Los Angeles, California.

Keffer, Frederic Department of Physics, University of Pittsburgh, Pittsburgh, Pennsylvania.

Last reviewed:January 2020

DOI:https://doi.org/10.1036/1097-8542.190700

That branch of magnetism which treats of diamagnetic phenomena and of the properties of diamagnetic bodies. Diamagnetism is a property exhibited by substances with a negative magnetic susceptibility, that is, by substances which magnetize in a direction opposite to that of an applied magnetic field. A diamagnetic substance has a magnetic permeability less than 1, and is repelled when placed near a magnet. The magnetization of diamagnetic substances is associated with the currents induced on application of a magnetic field. According to Lenz's law, the flow of an induced current is in such a direction as to oppose the change of flux of the inducing field; this accounts for the negative susceptibility. The diamagnetic susceptibility is invariably small, of the order of −10⁻⁵ cm³/mole. See also: Lenz's law; Magnetic susceptibility

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