ABSTRACT
This chapter discusses the mechanisms by which a dielectric material gets polarized, that is, a dielectric material acquires a net dipole moment when influenced by an external electric field. It examines a simple molecular model used to understand the linear behaviour of dielectric, that is, characteristics of a large number of dielectric materials. Atoms of all dielectric materials consist of charged constituents such as electrons and nucleus, which could be displaced, albeit through a small distance, by an external electric field. The molecules of dielectric materials, which are the basic building blocks of the material, either have zero dipole moment or have some permanent dipole moments depending on their structure. The term piezoelectricity refers to the fact that when a dielectric is mechanically stressed, then an electric field is produced within the dielectric. Electrets can be prepared from different dielectric materials depending on their structures and properties.
