O'Reilly logo

Engineering Physics by S. Mani Naidu

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

7.7 Domain theory of ferromagnetism

In 1907, Weiss proposed domain theory to explain ferromagnetism. According to this theory, a single crystal of ferromagnetic solid compresses a large number of small regions, and each region is spontaneously magnetized to saturation extent called a domain as shown in Fig. 7.6. The domain size may vary from 10−6 to the entire volume of the crystal. The spin magnetic moments of all the atoms in a domain are oriented in a particular direction. The magnetization directions of different domains of the specimen are random so that the resultant magnetization of the material is zero in the absence of an external magnetic field. These domains arise because the energy is not minimum when a large specimen has a uniform ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required