Overview
Nano-scale effects on electrical conduction: The recent and rapidly growing interest in nanostructured electroceramics has to go hand in hand with a better understanding of the nature of the interface, as their overall electrical properties are expected to be controlled predominantly by the interface. If the size of the crystal (the grain), and thus the distance between neighboring interfaces (the grain boundary or the surface) is reduced, the overall transport properties may substantially change due to the increased interface to volume ratio. Consequently, the main focus of interest is determination, tuning and prediction of the electrical charge carrier concentrations at the interface in nanosized conducting solids. Whereas the control parameters of charge carrier concentrations in the crystal interior are relatively well understood, little is known, to date, about those at the interface. The other important aspect that has yet to be addressed is the interfacial charge carrier mobility, which likely differs from that in the crystal interior. We have interests in pursuing investigations of those key interfacial variables of nanosized ionic and mixed conductors in one, two and three dimensions. Based on the precise knowledge of such variables our goal is to develop new types of electrochemical devices such as intermediate temperature fuel cells and sensors by utilizing/manipulating the interfaces of the materials. Our main experimental techniques are AC impedance spectroscopy and DC measurements (potentiometric and galvanometric)
