ABSTRACT
This chapter discusses the fundamentals of ferroelectricity. Ferroelectrics are utilized in various devices such as high-permittivity dielectrics, pyroelectric sensors, piezoelectric devices, electro-optic devices, and positive temperature coefficient of resistivity components. The word electrostriction is used in a general sense to describe electric-field-induced strain, and hence frequently also implies the "converse piezoelectric effect." In insulating materials, the application of an electric field can also cause deformation. This is called electric-field-induced strain. An almost linear strain curve in piezoelectric lead zirconate titanate (PZT) becomes distorted and shows large hysteresis on increasing applied electric field level, which is due to the polarization reorientation. Quartz and zinc oxide are popular piezoelectrics, but non ferroelectric materials. PZT solid solution systems were discovered in 1954 by Japanese researchers, Gen Shirane, Etsuro Sawaguchi et al. polyvinylidene difluoride is a polymer with monomers of CH2CF2. Since H and F have positive and negative ion-ization tendency, the monomer itself has a dipole moment.
