ANTI FERRO AND FERRI MAGNETIC SUBSTANCES

ANTI FERROMAGNETISM

In anti-ferromagnetic substances the spin of dipoles (direction of magnetic moment )of neighborhood domain is equal and opposite in direction.
Examples are Mns, MnO4, FeO, FeCl2 etc.
The susceptibility of anti-ferromagnetism is positive.
These materials exhibit a very low external magnetic field.
The susceptibility decreases with temperature of the material.
They obey Curie’s law. It means if their temperature is increased, they behave as para magnetic substances beyond Curie temperature.

FERRIMAGNETISM (OR FERRITES)

FERRI MAGNETIC MATERIALS ARE ALSO CALLED FERRITES.
These materials produce strong external filed and hence they are used to prepare strong electromagnets.
The direction of magnetic moment of neighborhood domain is not equal but it is in opposite direction.

The examples are MnFe2O4, FeFe2O4 CuFe2O4 etc.

Applications of ferrites:

They are used in the receivers of televisions, and radios .
Used in microwave devices, digital computers, electrical communication devices.

They are used in remote control toys.

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