(i) What is the cause of ferromagnetism in some materials?(ii)What is meant by a non-stoichiometric oxide?(iii)Explain the difference between strong field and weak field.

Question

Abbigail Vaughn · Accepted Answer

What is the cause of ferromagnetism in some materials?Ferromagnetism is a unique magnetic behaviour that is exhibited by certain materials such as iron, cobalt, alloys, etcIn a ferromagnetic material in the unmagnetized state, atomic dipoles in small regions called domains are aligned in the same direction. The domains exhibit a net magnetic moment even in the absence of an external magnetizing field.However, the magnetic moments of neighbouring domains are oriented in opposite directions. They cancel out and therefore the net magnetic moment of the material is zero. On applying external magnetic field these domains all align themselves in the direction of the applied field. In this way, the material is strongly magnetized in a direction parallel to the magnetizing field.