What is Polarization?
The orientation of a dipole along the applied electric field is
called polarization (P). It causes charge density to increase over that of a vacuum
due to the presence of the dielectric material so that
D =ε₀E + P.E is the electric field.D is the surface charge density of a capacitor, also called
dielectric displacement.
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| Polarization |
Types of Polarization:
There are four types of polarization: Electronic, Ionic, Orientation, and
Space charge (interfacial).
Electronic polarization:
Electronic polarization is caused by the displacement of the center of
the electron cloud around the nucleus under the applied field.
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| Electronic Polarization |
Ionic polarization:
Ionic polarization happens in ionic material as the applied
electric field displaces the cations and anions in opposite
directions resulting in a net dipole moment.
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| Ionic Polarization |
Orientation polarization:
Orientation polarization occurs in materials having
permanent dipole moments. The rotation of the permanent
moment in the direction of the applied field causes polarization in this case.
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| Orientation Polarization |
Space charge polarization:
Space charge polarization arises from the accumulation of
charge at interfaces in a heterogeneous material consisting of
more than one phase having different resistivity. 
