Residual Magnetization

Magnetization, Residual

 

also remanent magnetization or remanence), the magnetization Jr that a ferromagnetic material has when the intensity of the external field is zero. Residual magnetization depends both on the magnetic properties of the material and on the previous magnetic history of the material—the nature of previous effects of a magnetic field on the material. The value of the residual magnetization of specific ferromagnetic specimens depends considerably on the shape of the specimens (this dependence is expressed by the action of the demagnetization factor). High-coercivity ferromagnets have the most stable residual magnetization. When ferromagnets are heated to a temperature above the Curie point, they lose their ferromagnetic properties and, at the same time, their residual magnetization. Mechanical vibrations also reduce the residual magnetization. Residual magnetization has extensive practical applications.

References in periodicals archive ?
From the measured magnetization property, the sintered Si nanopolycrystalline body includes a ferromagnetic phase because of the residual magnetization and coercive force as shown in Figures 3(a) and 3(b).
where [B.sub.r] is the residual magnetization (in this work, Br = 1.19 [T]) and L is the distance between the poles of the magnet.
"This is the point of residual magnetization, the partial magnetization that remains from the full current from the past, now turned off--representing the iron's 'remembering' its history."
As the engineer drew his hysteresis magnetization curves, I looked over his shoulder and reframed, for sport, his terminologies from the upper right quadrant of his graph as follows: his "a," "fully magnetized," I changed to "fully traumatized"; "b," his "residual magnetization" (magnetic memory), I changed to "residual traumatization" (memory of the trauma); and "o," his "initial nonmagnetized state," I changed to the "initial nontraumatized state," to which the person never returns, that is, with no evidence of having been exposed to the traumatizing circumstance.
The observed residual magnetization of analysed magnetic field sensor LSM303DLH and auxiliary elements (R, C) was achieved at magnetic field strength of 20 G.
where [[mu].sub.rm] is the relative recoil permeability of PMs, and [bar.M] is the residual magnetization vector.
Because the velocity/voltage measurement is magnetically passive, it will measure the background magnetic field, as well as residual magnetization, without current flowing during the measurement.
[M.sub.0] = saturation magnetization [H.sub.M] = internal magnetic field at saturation [B.sub.M] = magnetic induction at saturation [B.sub.r] = residual magnetic induction [M.sub.r] = [[Mu].sub.0][B.sub.r] (the residual magnetization)
These curves do not present retentivity or coercivity, characteristic of materials with the absence of residual magnetization after removal of the magnetic field.
Panov, Residual Magnetization of Ultrafine Magnets, FESTU Press, Vladivostok, Russia, 2004.