Mechanism of Polarization

First, we need to define polarization. Polarization is the alignment of dipole moments in response to an external electric field. The mechanism of polarization explains how molecules or atom react to this field, leading to the positioning of dipoles.
There are fundamentally four divisions of polarization mechanisms. They are Electronic polarization, dipolar or Orientation polarization, Ionic polarization and Interfacial polarization. Let us discuss the different polarization in detail.

Electronic Polarization

Electronic Polarization occurs when neutral atoms get polarized, causing electrons to shift. This is also called atomic polarization. Simply put, the center of the electrons shifts relative to the nucleus, forming a dipole moment.

Orientation Polarization

Orientation Polarization, also known as dipolar polarization, happens when dipoles align in response to an electric field. In a normal state, dipoles are randomly aligned due to thermal equilibrium. When an electric field is applied, they align to some degree, as seen in gases and liquids like H₂O and HCl.

Ionic Polarization

Ionic Polarization involves the polarization of ions, leading to the shifting of ions and the formation of dipole moments. This typically occurs in solid materials like NaCl. In a normal state, these dipoles cancel each other out.

Interfacial Polarization

Interfacial Polarization, also called space charge polarization, occurs at the interface of an electrode and material due to an external electric field. Positive charges move to the grain boundary, causing an accumulation of charges.

However, in most of the cases more than one polarization will be present in one material. Electronic polarization happens in almost all materials. So for us, the dielectric characterisation of real materials can be really difficult. For finding the total polarization, we will consider all the other polarizations except interfacial polarization. The reason is that, we have no method for computing the charges present in interfacial polarization.

When we go through the four polarization mechanism, we can see that the volume of the drifted entities is different for each of them. It can be seen that the gradual increase in mass happens from electronic to orientation polarization. The frequency of the peripheral electric field has direct relation with these mass. So we can conclude that, when mass to be drifted increases, the time for drifting it also increases.
Next, we can discuss about how the dielectric constant of the non-magnetic dielectrics which comes from the electrical part is connected to refraction index (at high frequency 10¹²-10¹³ Hz). It is by

For example C (Diamond) has and n² is 5.85 and dominant polarization is electronic. For Ge, and n² is 16.73 having electronic polarization. For H²O, and n² = 1.77 having electronic, dipolar and ionic polarization.