1. Superlattices of Perovskite Structured Materials for Solid Oxide Fuel Cells
Yayoi Takamura, Department of Chemical Engineering and Materials Science, UC Davis, Davis, CA
A novel route to developing new materials with properties tailored for specific applications such as the cathode of solid oxide fuel cell, involves harnessing the unexpected physical phenomena that result from the changes in structure and chemistry which occur over nanometer scales at surfaces and interfaces. We have grown epitaxial superlattices consisting of alternating layers of La0.7Sr0.3MnO3, La0.7Sr0.3FeO3, and La0.7Sr0.3CoO3 with sublayer thicknesses ranging from three to 18 unit cells. Detailed structural and chemical characterization reveals that an electronic reconstruction occurs at the interfaces and that the nature of the reconstruction is determined by the chemical composition and thickness of each layer. …
The electronic reconstruction directly impacts the resistivity behavior of the chemicall equivalent the superlattices and associated solid solution film. The resistivity varies by over three orders of magnitude at room temperature and can be tailored through the choice of the thickness of each layer.