Multifunctional Complex Oxide Processing

Abstract

Among the complex functional materials, such as semiconductors, metals, and polymers, ceramics are a most likely class of materials with the widest variety of functions for desired technological application, such as capacitors, power transducers, gas and biological sensors, and electrooptical and electro-chromic devices. In crystalline materials of type ABX3, the properties are due to some intrinsic characteristics as there is no center of symmetry, crystalline anisotropy, spontaneous and reversible-oriented dipoles, degree of order-disorder, bandgap energy, and the presence of intrinsic or promoted defects by former or modifier lattice; these are some decisive points in the characteristics of these compounds. Considering this broad range of intrinsic and extrinsic parameters that determine the functionality and efficiency of this class of complex and multifunctional materials, the processing procedure is a crucial step. The different syntheses routes that provide to get control of composition, crystal structure, morphology, and size as well as type and location of defects allow obtaining complex compounds with synergy between properties for many applications. The goal of this chapter is to present different processing routes and discuss what are the most appropriate depending on the desired applications. In this chapter, the processing of the complex oxide perovskite type as titanates, niobates, tungstates; semiconductors such as (Zn-Nb-Co-Cr)-SnO2 and Au-ZnO modified systems will be presented. The materials which will be discussed here present a potential applications as piezoelectrics, photoluminescent, photocatalyst, sensors, oxide electrodes, varistor, and solar cells devices.