Dielectric
These materials are sometimes act as conductors and the conductivity depend upon the type of materials so these are know as dielectric materials various dielectric materials are shown in the below slides
Unit V Dielectrics
Dielectrics are a class of material which respond to external electric fields. An external electric field can cause the center of positive and negative charges in the crystal to shift from their mean position. This separation of charges results in creation of dipoles in the system. The net dipole moment created per unit volume is called the polarization. The polarization in the material is dependent on the net electric field experienced by the dielectric.
Dielectric Materials
Engineering Physics, 1st year dielectric constant flash cards.
Capacitors and dielectric
These are some book notes of topic capacitors and dielectric.