A fascinating problem in solid state ionics is the role of interfaces in mass and charge transport. Of particular interest for pure oxides is the case where the grain size (or film thickness) ap-proaches lengthscales which could be comparable to the space charge region. In alio-valently doped oxides, a further complication is cation segregation at interfaces or surfaces which can affect both carrier concentration and mobility. Under such conditions, it may be possible to observe conduction phenomena typically not seen in bulk. In this presentation, I will discuss our on-going investigation on high temperature carrier transport in interface-controlled oxides using thin films and superlattices as model systems. The effect of oxygen partial pressure on electrochemical conduction as well as phase formation and stability boundaries will be high-lighted. Approaches to modulate point defect concentration in complex oxides controllably using photons will be presented. Subsequently, relevance to energy conversion technologies such as solid oxide fuel cells as well as synthesis of novel interfacial energy materials will be pointed out.
Contributions from group members will be highlighted in the presentation
Shriram Ramanathan received his undergraduate degree in Metallurgical Engineering from Indian Institute of Technology, Madras, M.S. in Materials Engineering from University of Houston and Ph.D. in Materials Science and Engineering from Stanford University in 2002. Prior to joining Harvard University as a junior faculty member, he was a researcher at Components Research, Intel in the areas of wafer bonding science and three-dimensional integrated circuits. His research interests are in understanding synthesis-structure-property relationships in oxides.
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