Question

Compare dia, para and ferromagnetism.

How is ferromagnetism different from paramagnetism?

Answer 1

	Diamagnetism	Paramagnetism	Ferromagnetism
1.	A force tends to move the material from the stronger part to the weaker part of the external field.	Weak magnetism in the direction of the applied field.	Strong magnetism in the direction of the applied field.
2.	Each electron has finite orbital magnetic dipole moments.	Each atom has a net magnetic dipole moment.	Have a net dipole moment as in a paramagnetic material.
3.	Since the orbital planes are orientated in a random manner, the vector sum of magnetic moments is zero.	Due to the random orientation of the magnetic moments, the net magnetic moment of the material is zero.	Within each domain, the magnetic moments are spontaneously aligned in a direction.
4.	The resultant magnetic moment for each atom is zero.	There is a net magnetic dipole moment induced in the direction of the applied field.	Since the direction of magnetisation varies from domain to domain, the net magnetisation of the specimen is zero.
5.	E.g.: Bismuth, copper, water, etc.	E.g.: Aluminium, platinum, oxygen, etc.	E.g.: Iron, cobalt, nickel, etc.