CAREER: Multifunctional Heterostructures of Perovskite Structured Materials

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NON-TECHNICAL DESCRIPTION: The development of next generation spintronic devices, sensors, and low temperature solid oxide fuel cells requires the development of materials with new functional properties not found in conventional bulk materials. A novel route involves harnessing the unexpected physical phenomena that result from the changes in structure and chemistry which occur over nanometer scales at surfaces and interfaces. The approach of this work utilizes laser-assisted growth to control interfacial properties with atomic layer precision in combination with state-of-the-art techniques for characterizing the structural and chemical properties. In this way, a full understanding of the origins of new magnetic and electronic properties derived from interfacial mechanisms can be determined. The research activities involve training of undergraduate and graduate researchers, including under-represented minorities through the NSF California Alliance for Minority Participation (CAMP) program. Furthermore, a Science, Technology, Engineering, and Mathematics (STEM) workshop brings educationally disadvantaged students from community colleges around Northern California to UC Davis to experience first hand what the science and engineering programs at UC Davis can offer them. TECHNICAL DESCRIPTION: The objective of this CAREER proposal involves understanding and harnessing surface and interfacial phenomena in artificial heterostructures and nanocomposites which possess multiple functional properties as needed for next generation spintronic devices, sensors, and low temperature solid oxide fuel cells. Perovskite structured materials are chosen as the platform for this work for their diverse and tunable functional properties. The unique aspect of this work involves the combined expertise in two equally important areas. First, heterostructures and nanocomposites with precisely controlled chemical and structural parameters are grown by pulsed laser deposition. Nanocomposites consisting of isolated islands embedded in a matrix are defined by a structural modification through a two-step process of e-beam lithography followed by ion implantation. Second, sophisticated characterization techniques are used to carefully probe both the local surface and interfacial properties and their effect on the overall global functional properties. In particular, synchrotron radiation based techniques which offer surface sensitive and chemically selective information on the electronic structure and magnetic characteristics of each layer are employed. Together, these steps provide a means of gaining a fundamental understanding of surface and interfacial effects which can be harnessed towards the control of the multifunctionality of materials systems.