Dielectrics

Abstract

Dielectric materials are insulators characterized by the response to an electric field. An ordinary dielectric, such as water, placed in the presence of an electric field acquires an electric polarization that disappears when the field is removed. For small values of the applied electric field E, the polarization (electric dipole moment per unit volume) of an ordinary dielectric is proportional to the field, that is,

$$\displaystyle{ \mathcal{P} =\bar{\chi } E, }$$

(15.1)

where $\bar{\chi }$ is the constant of proportionality.