Investigations of Tungsten-Bronze Ferroelectric Ceramics

Ferroelectricity is a property of certain materials which possess a spontaneous electric polarization that can be reversed by the application of an external electric field. Ceramics possessing this property are known as Ferroelectric Ceramics. Some of the most important applications of ferroelectric ceramics include nonvolatile memories, high-dielectric constant capacitors, pyroelectric, piezoelectric and electro-optic sensors. On structural basis, ferroelectric ceramics can broadly be classified as Perovskites, Tungsten-Bronze, Bismuth Layered Structure Ferroelectric (BLSF) and Pyrochlore. The Tungsten Bronze (TB)-type structure having a general formula (A1)4(A2)2(C)4(B1)2(B2)8O30 consists of a complex array of distorted BO6 octahedra sharing corners in such a way that three different types of interstices (i.e. A, B and C) are available for cation substitutions in which a wide variety of substitutions can be made for different applications. The present work describes the detailed structural and electrical properties of Tungsten-Bronze ferroelectric ceramics.