Question

Difference between diamagnetic paramagnetic and ferromagnetic.

Answer 1

Diamagnetic Material

• A material that turns at a right angle to the field by producing a magnetic response opposite to the applied field is called diamagnetic material
• For example: Silver, copper, and carbon have slightly less permeability than free space (for copper, μ_r= 0.9999980).

Paramagnetic Material

• A material aligning itself with the applied field is called paramagnetic material.
• Paramagnetic materials such as aluminium and air have permeability slightly greater than that of free space (for air μ_r =1.0000004).

The effects of diamagnetic and paramagnetic are negligibly small so that materials possessing these weak phenomena are said to be non-magnetic.

Ferromagnetic Material

• Within the paramagnetic class of materials, is a special classification of materials called ferromagnetic material.
• These materials are strongly attracted to magnets and exhibit Paramagnetism to a phenomenal degree.
• Ferromagnetic materials such as iron, steel, cobalt and their alloys have relative permeability extending into the hundreds and thousands, and are said to be magnetic.

PROPERTIES	FERROMAGNETIC MATERIALS	PARAMAGNETIC MATERIALS	DIAMAGNETIC MATERIALS
State	They are solid.	They can be solid, liquid or gas.	They can be solid, liquid or gas.
Effect of Magnet	Strongly attracted by a magnet.	Weakly attracted by a magnet.	Weakly repelled by a magnet.
Behavior under non-uniform field	Tend to move from low to high field region.	Tend to move from low to high field region.	Tend to move from high to low region.
Behavior under external field	They preserve the magnetic properties after the external field is removed.	They do not preserve the magnetic properties once the external field is removed.	They do not preserve the magnetic properties once the external field is removed.
Effect of Temperature	Above the curie point, it becomes paramagnetic.	With the rise of temperature, it becomes diamagnetic.	No effect.
Permeability	Very high	Little greater than unity	Little less than unity
Susceptibility	Very high and positive	Little greater than unity and positive	Little less than unity and negative
Examples	Iron, Nickel, Cobalt	Lithium, Tantalum, Magnesium	Copper, Silver, Gold