In the earlier article, I have explained the electronic polarization. Today we will discuss the ionic polarization.

Ionic polarization. As the name suggests, ionic polarization occurs in ionic materials. It occurs when an electric field is applied to an ionic material then cations and anions get displaced in opposite directions giving rise to a net dipole moment.

Example : Polyatomic gases

In absence of electric field E, the distance  between the ions is d but in presence of electric field, distance between the ions  increases

The dipole moment p for each ion pair is equal to the product of charge on each ion and relative displacement.

That is p = qd

Thus ionic polarization is given as

P_e =n α_iE

where α_i is constant of proportionality known as ionic  polarizability constant.

This polarization is independent of temperature.