Explain the magnetisation- curves of magnetic materials.

The major characteristic of a ferromagnetic substance is domain structure of it. Every crystal of a ferromagnetic substance contains a perpendicular crystallographic direction along that it is most simply magnetized. Higher fields are needed to magnetize single crystals along several other directions. With small external fields the domain wall movements are reversible, corresponding to the identified reversibility of the initial portion of the magnetization curve. Inside somewhat higher fields, these boundary movements continue but are frequently irreversible and larger. The irreversible movements arise mostly in the steep part of the magnetization curve and at last result in all favourably oriented domains reaching their greatest size. At that stage each domain is magnetized yet in what is locally the easiest direction. Application of until now higher fields twists the magnetization in the field direction that is domain rotation and away from the simple directions, therefore storing up energy.

Magnetization Curve