Barnett Effect


Barnett effect

[′bär·nit i′fekt] (electromagnetism) The development of a slight magnetization in an initially unmagnetized iron rod when it is rotated at high speed about its axis.

Barnett Effect

 

the magnetization of ferromagnets during their rotation in the absence of a magnetic field. It was discovered in 1909 by the American physicist S. Barnett. The Barnett effect is explained by the fact that during the rotation of an object the angular momentum and the magnetic moment of the atoms associated with it are altered. A component of the magnetic moment appears along the rotational axis. The Barnett effect, like other magnetomechanical phenomena, makes it possible to obtain important information on the nature of the carriers of the magnetic moment in a substance. The magnetomechanical ratio (the ratio of the magnetic moment of the atom to its angular momentum) for various substances was determined by means of the Barnett effect, and the conclusion was drawn that the ferromag-netism in metals and alloys of the iron group is due primarily to the magnetic spin moment of the electron.

R. Z. LEVITIN