[Home]History of Superparamagnetism

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Revision 3 . . (edit) August 17, 2001 3:34 am by Mike Dill
Revision 2 . . August 16, 2001 4:58 am by Stokerm
Revision 1 . . August 15, 2001 6:22 am by Stokerm
  

Difference (from prior major revision) (minor diff, author diff)

Changed: 1c1
Superparamagnetism is a phenomena by which magnetic materials may exhibit a behavior similar to paramagnetism at temperatures below the Curie or the Neel temperature.
Superparamagnetism is a phenomena by which magnetic? materials may exhibit a behavior similar to paramagnetism at temperatures below the Curie or the Neel temperature.

Changed: 5c5
Superparamagnetism occurs when the material is composed of very small crystallites (1-10 nm). In this case even though the temperature is below the Curie or Neel temperature and the thermal energy is not sufficient to overcome the coupling forces between neighboring atoms, the thermal energy is sufficient to change the direction of magnetization of the entire crystallite. The resulting fluctuations in the direction of magnetization cause the magnetic field to average to zero. Thus the material no longer exhibits magnetic behavior.
Superparamagnetism occurs when the material is composed of very small crystallites (1-10 nm). In this case even though the temperature is below the Curie or Neel temperature and the thermal energy is not sufficient to overcome the coupling forces between neighboring atoms, the thermal energy is sufficient to change the direction of magnetization of the entire crystallite. The resulting fluctuations in the direction of magnetization cause the magnetic field to average to zero. The material behaves in a manner similar to paramagnetism, except that instead of each individual atom being independently influenced by an external magnetic field, the magnetic moment of the entire crystallite tends to align with the magnetic field.

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