magnetic susceptibility

magnetic susceptibility
the coefficient or set of coefficients of the magnetic intensity in any expression giving the components of magnetization as linear combinations of the components of magnetic intensity. Also called susceptibility.

* * *

      quantitative measure of the extent to which a material may be magnetized in relation to a given applied magnetic field. The magnetic susceptibility of a material, commonly symbolized by χm, is equal to the ratio of the magnetization M within the material to the applied magnetic field strength H, or χm = M/H. This ratio, strictly speaking, is the volume susceptibility, because magnetization essentially involves a certain measure of magnetism (dipole moment) per unit volume.

      Magnetic materials may be classified as diamagnetic, paramagnetic, or ferromagnetic on the basis of their susceptibilities. Diamagnetic materials, such as bismuth, when placed in an external magnetic field, partly expel the external field from within themselves and, if shaped like a rod, line up at right angles to a nonuniform magnetic field. Diamagnetic materials are characterized by constant, small negative susceptibilities, only slightly affected by changes in temperature.

      Paramagnetic materials, such as platinum, increase a magnetic field in which they are placed because their atoms have small magnetic dipole moments that partly line up with the external field. Paramagnetic materials have constant, small positive susceptibilities, less than 1/1,000 at room temperature, which means that the enhancement of the magnetic field caused by the alignment of magnetic dipoles is relatively small compared with the applied field. Paramagnetic susceptibility is inversely proportional to the value of the absolute temperature. Temperature increases cause greater thermal vibration of atoms, which interferes with alignment of magnetic dipoles.

      Ferromagnetic materials, such as iron and cobalt, do not have constant susceptibilities; the magnetization is not usually proportional to the applied field strength. Measured ferromagnetic susceptibilities have relatively large positive values, sometimes in excess of 1,000. Thus, within ferromagnetic materials, the magnetization may be more than 1,000 times larger than the external magnetizing field, because such materials are composed of highly magnetized clusters of atomic magnets (ferromagnetic domains) that are more easily lined up by the external field.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Magnetic susceptibility — Susceptibility Sus*cep ti*bil i*ty, n.; pl. {Susceptibilities}. [Cf. F. susceptibilit[ e].] 1. The state or quality of being susceptible; the capability of receiving impressions, or of being affected. [1913 Webster] 2. Specifically, capacity for… …   The Collaborative International Dictionary of English

  • Magnetic susceptibility — In electromagnetism, the magnetic susceptibility χm (latin: susceptibilis “receptiveness”) is a dimensionless proportionality constant that indicates the degree of magnetization of a material in response to an applied magnetic field. A related… …   Wikipedia

  • magnetic susceptibility — magnetinė juta statusas T sritis Standartizacija ir metrologija apibrėžtis Apibrėžtį žr. priede. priedas( ai) Grafinis formatas atitikmenys: angl. magnetic susceptibility vok. magnetische Suszeptibilität, f rus. магнитная восприимчивость, f pranc …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • magnetic susceptibility — magnetinė juta statusas T sritis fizika atitikmenys: angl. magnetic susceptibility vok. magnetische Suszeptibilität, f rus. магнитная восприимчивость, f pranc. susceptibilité magnétique, f …   Fizikos terminų žodynas

  • magnetic susceptibility — noun : susceptibility 3a * * * Elect. the coefficient or set of coefficients of the magnetic intensity in any expression giving the components of magnetization as linear combinations of the components of magnetic intensity. Also called… …   Useful english dictionary

  • magnetic susceptibility — noun a measure of the magnetization of a material per unit of applied magnetic field …   Wiktionary

  • magnetic susceptibility — /mægˌnɛtɪk səsɛptəˈbɪləti/ (say mag.netik suhseptuh biluhtee) noun the ratio of the intensity of magnetisation produced in a substance to the intensity of the magnetic field to which it is subjected …   Australian-English dictionary

  • magnetic susceptibility — Смотри Восприимчивость магнитная …   Энциклопедический словарь по металлургии

  • molar magnetic susceptibility — molinė magnetinė juta statusas T sritis fizika atitikmenys: angl. molar magnetic susceptibility vok. molare Suszeptibilität, f; Molsuszeptibilität, f rus. молярная магнитная восприимчивость, f pranc. susceptibilité magnétique molaire, f …   Fizikos terminų žodynas

  • volume magnetic susceptibility — tūrinė magnetinė juta statusas T sritis fizika atitikmenys: angl. volume magnetic susceptibility vok. Volumensuszeptibilität, f; Volumsuszeptibilität, f rus. объёмная магнитная восприимчивость, f pranc. susceptibilité magnétique volumique, f …   Fizikos terminų žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”