Issues involving properties of oxides at nm size scales are limiting in several emerging technologies, including ferroelectric DRAM, chemical micro sensors, and microwave filters for wireless communications. While several accurate tools exist for structure determination in solids, local property variations have been much less accessible. The application of Scanning Probe analysis has yielded considerable insight as to size dependent properties and surface or interface mediated behavior of ceramics. We have used atomic resolution STM of transition metal oxide surfaces to show that compositional variations are accommodated through the stabilization of surface phases, as well as by surface reconstruction. Recent studies in our lab focus on perturbation of local properties near interfaces. Electric field variation at field emitter arrays, size dependent contact potential at metal cluster/oxide interfaces, the atomic basis of potential at oxide grain boundaries, limitation to current flow in superconductors, and ferroelectric phase transformations are examples where nanometer scale property variations dictate behavior. Comparison of in situ measurements to continuum or quantum mechanical models are used to elucidate fundamental behavior.
