Showing posts with label Ferromagnetic. Show all posts
Showing posts with label Ferromagnetic. Show all posts

Saturday, November 3

Ferromagnetic Domains

Introduction to ferromagnetic domains:
The ferromagnetic substances are those in which each individual atoms or molecules or ions have a non zero magnetic moment as in the paramagnetic substances. When the ferromagnetic substances are placed in an external magnetizing field, they get strongly magnetized in the direction of the field. Ferromagnetism has been explained by Weiss on the basis of domain theory in addition to the usual electron theory.Please express your views of this topic Ferromagnetic Metals by commenting on blog.

Domains in Ferromagnetic Substances

The each atom of a ferromagnetic substance is a tiny magnetic dipole having permanent dipole moment. However in ferromagnetic materials, atoms form a very large number of small effective regions called domains. Each domain has a linear dimension of 1000 A° and contains about 1010 atoms. Within each domain a special interaction called exchange coupling renders dipole moments of all the atoms in a particular direction. Thus each domain is a strong magnet without any external magnetic field. In spite of this, a ferromagnetic substance does not behave as a magnet, because in the absence of the external magnetic field, the magnetic moments of the different domains are randomly oriented so that their resultant magnetic moment in any direction is zero.Is this topic Permanent Magnet Generator for Sale hard for you? Watch out for my coming posts.

When an external magnetic field is applied on the ferromagnetic substance, it gets strongly magnetized. This can be explained as follows:

(i) Displacement of boundaries of the domains, i.e., domain which are oriented in the direction of the applied field increase in size and the domains which are oriented opposite to the field deceases in size.

(ii) Rotation of domain, i.e., the domain rotate till their magnetic moments are aligned in the direction of the applied magnetic filed. This would happen only when the magnetic field applied is very strong.

                                                   Image of the ferromagnetic domains

Conclusion for the Ferromagnetic Domains

From the above discussion we can say that when the domains have aligned along the magnetic field and amalgamated to form a single giant domain. This is how ferromagnetic material gets strongly magnetized in the direction of the applied field. The examples of the ferromagnetic materials are iron, cobalt, nickel and some are the rare earth materials as gadolinium and dysprosium.