Fundamental physics and promising applications of superionic conductors

Recently, superionic conductors (SIC’s) have been considered to be a key material for several application fields as well as energy engineering and ceramic technology. We review the recent stage of the basic models and concepts for the physical understanding of high-speed ionic transport in solids. In the latter part of this paper, we briefly review the applications of SIC’s to solid-state fuel cells and sensors. As a new application of SIC’s, we introduce a technique developed on a complex system consisting of an oxygen ionic conductor and high-Tc oxide super-conductors. Finally, we introduce the possibility of the application of SIC’s to optical devices.