4 - Perovskite layer-structured ferroelectrics

Abstract

Ferroelectric systems are important materials with a wide range of industrial and commercial applications. Since the discovery of the ferroelectricity, ferroelectrics have been the heart and soul of several multimillionaire companies, ranging from high-dielectric-permittivity capacitors to the development of piezoelectric transducers, pyroelectric sensors, and others. The only drawback in the whole technology has been the environmentalist’s nightmare of its dependence on a 60%-lead-containing family of materials. Over the last 20 years, however, there has been an enormous effort in developing lead-free ferroelectrics in order to obtain good dielectric, ferroelectric, piezoelectric, and pyroelectric properties when compared to the conventional lead-based ferroelectrics. An important group of lead-free ferroelectric materials belong to the Aurivillius family (perovskite layer structured ferroelectrics), which are characterized by large remnant polarization, high Curie temperatures, and good piezoelectric properties. This review presents a general overview on the progress in the studies of the ferroelectric systems from the Aurivillius' family, including (1) structural studies, (2) dielectric and electric behavior, and (3) piezoelectric and pyroelectric properties.