10 - Effect of rare-earth elements on perovskite composite materials

Abstract

Perovskites, a very prominent and outstanding class of materials, include perovskite oxides and metal halides that have a significant role in various multifunctional devices. Perovskite materials have been studied extensively for devices because of their stable crystal structure similar to CaTiO3 or ABX3 which exhibits intriguing and unusual physical properties. The structure and exceptional tolerance factor of the perovskites of the types: simple, layered, double, and triple systems give unique properties desired for the application. Tailoring of these systems chemically through partial substitution of the cationic site(s) with other metal ions modifies the structural, microstructural, dielectric, electrical, ferroelectric, magnetic, and optical properties of the parent perovskite. In comparison with the undoped perovskite oxides, the rare-earth element doped host exhibits much more diverse multiferroic and electrical properties. The distinguished properties in the host due to rare-earth doping are because of the change in valence states of the different cations at different sites due to the rare-earth element plays a major role in regulating the transport properties. This chapter is an overview on the effects of various rare-earth elements on the perovskite composite materials. It includes the origin and history behind the development of the perovskite systems, the structure, stability, and classifications of the perovskite systems, various synthesis methods used to produce these systems, reviews on various rare-earth-doped perovskite systems developed for various applications, especially for energy storage devices, memory and sensor devices, photovoltaic devices, optoelectronics, catalysts, magnetic devices, biomedicine, and many more. The review concludes with various perspectives and challenges in the research carried out today and the scope for future studies that can be adopted to develop even more efficient systems for future devices.