Technical: This project focuses on thin film oxide heterostructures. The objective is to understand novel magnetic and electronic phenomena associated with the interface between two dissimilar transition metal oxides through achievement of atomically smooth spinel structure oxide interfaces. Understanding how imbalances in valence, bandwidth and interaction lengths at the interface give rise to charge redistribution and magnetic and orbital order at the interface different from the bulk forms the basis of the project. Isostructural complex oxide heterostructures provide model systems where imbalances in valence, bandwidth and interaction length will be systematically studied. The approach includes: (i) synthesis of atomically smooth, spinel structure oxide thin films; (ii) synthesis of isostructural heterostructures with atomically sharp interfaces; (iii) local electronic and magnetic characterization of surfaces and interfaces by X-ray magnetic circular dichroism (XMCD), photoemission electron microscopy (PEEM), X-ray resonant scattering (XAS), magnetic force microscopy (MFM), transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS); and (iv) electronic transport and magnetic characterization of heterostructures. Fundamental understanding of the role of band structures, electron densities, and interaction length imbalances on charge redistribution and magnetic and orbital order at the interface different from the bulk is sought. New knowledge and understanding from this research is anticipated for oxide systems, and more broadly in interface physics and materials science. Non-technical: The project addresses basic research issues in a topical area of materials science having high technological relevance. The research will contribute basic materials science knowledge at a fundamental level to new understanding and capabilities for potential next generation electronic/magnetic devices. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. The project includes graduate and undergraduate student activities in the laboratory and in the classroom through a magnetics curriculum which also extends to local high school students. An internship program will be continued with a local high school and the scope of this interaction is expected to grow over the next three years. Graduate and undergraduate students will have the opportunity to mentor these high school interns during parts of the school year and in the summer. In cooperation with physics teachers from the high school, a modular materials science curriculum will also be developed.
Project Outcome Report DMR#0604277 PI: Yuri Suzuki NSF funding supported an integrated research and education program based on the development of thin films of a family of complex materials called spinel structure compounds- the most well-known being lodestone, Fe3O4. This class of materials exhibits a wide range of electronic, magnetic and optical properties in the bulk that are promising for functional device applications. We have developed processes to synthesize these spinel structure materials in thin film form to incorporate them into thin film devices. Many of these materials exhibit properties not observed in the bulk and these properties, in turn, can be exploited in device applications. In this program, we have developed a number of these spinel structure materials in thin film form, demonstrated novel functional properties and the incorporated these materials into a new kind of hybrid magnetic device. These devices are promising for a more energy efficient spin based electronics architecture in the future. An important part of this program has been the educational component that has included high school students, undergraduates and graduate students. I have developed a high school internship program with a local Oakland high school that is now in its ninth year. In the program, the students participate during the academic year in short term research in the lab. This program was initiated in my research group and has been expanded to include polymer science and bioengineering groups as well. At the undergraduate level, I have employed over the summer months and during the academic year a number of students- most of whom have gone on to advanced degree programs. Graduate student training has been carried out not only in research but also in communication, teaching and collaboration skills.
