|When:||Tuesday, February 19, 2013|
4:00 PM - 5:00 PM
Technological Institute, L211 |
2145 Sheridan Road
Evanston, IL 60208 map it
|Audience:||- Faculty/Staff - Student - Public|
|Group:||Department of Materials Science and Engineering|
|Category:||Lectures & Meetings|
Please join us in welcoming Jeffrey Eastman, Materials Scientist from the Argonne National Laboratory, for our 2013 Winter Colloquium series.
Argonne National Laboratory
Tuesday, February 19, 2013
Tech L211, 4:00pm
"In-Situ Synchrotron X-ray Studies of the Synthesis and Behavior of Ferroelectric and Conducting Oxide Thin Film Heterostructures"
Intense interest is focused on the growth science and behavior of epitaxial oxide thin films because of continuing discoveries of new interesting and important properties. The key to achieving desired functionality of oxide heterostructures is the ability to synthesize high-quality films with full control of factors such as composition, crystallographic orientation, surface termination, and strain state. Many of the most promising thin film synthesis techniques involve non-vacuum, high-temperature environmental conditions that are difficult or impossible to probe using standard spectroscopic or structural probes. However, the use of high-energy X-rays available at synchrotron sources such as the Advanced Photon Source (APS) provides an opportunity to obtain real-time atomic-level structural and chemical information during synthesis, and to characterize post-growth behavior in high temperature controlled gas environments. This talk will describe results from two ongoing studies that both employ an in-situ X-ray approach to understand and control the synthesis behavior of complex oxide epitaxial thin film heterostructures. In one example I will describe how studies of the synthesis and ferroelectric behavior of epitaxial PbTiO3 thin films have revealed that the electrical boundary conditions imposed by the gas environment in contact with the sample can play a key role in controlling the equilibrium polarization structure. I will also describe a second study in which in-situ X-ray techniques are providing insight into the oxygen exchange behavior of La0.6Sr0.4Co0.2Fe0.8O3-d thin film heterostructures under controlled electrochemical potentials, relevant to the behavior of solid oxide fuel cell cathodes. Future plans aimed at understanding the possible interplay between ferroelectricity and conduction behavior in epitaxial heterostructures will also be described
Jeffrey Eastman was educated at the University of Illinois, Urbana-Champaign (B.S. and M.S. in Metallurgical Engineering) and at Cornell University (Ph.D. in Materials Science). His Ph.D. thesis work used transmission electron microscopy techniques to investigate the structure of grain boundaries in oxide materials. Following receipt of his Ph.D., he was awarded an Alexander von Humboldt Post-Doctoral Fellowship and spent two years in Stuttgart, Germany at the Max-Planck-Institut für Metallforschung, where he investigated the structure of metal-oxide heterointerfaces. In 1987 he joined the Materials Science Division of Argonne National Laboratory. His research at Argonne has probed the structures and properties of epitaxial oxide and nitride thin film heterostructures, as well as that of nanocrystalline materials. He has authored or co-authored over 140 publications and his work has been cited in the scientific literature more than 6600 times. His work has also resulted in five granted patents. He currently leads a program at Argonne focused on creating and characterizing novel conducting oxide heterostructures. The fundamental science discovered in this program is relevant to many envisioned future energy applications.