CAREER: Electrochemical Ceramics - Understanding the Gap between Localized and Collective Viewpoints of Electronic Structure

University Of Washington, Seattle WA

Investigators

Abstract

Electrochemical ceramics encompass a variety of present and emerging technologies, including gas sensors, fuel cells, gas-separation membranes, and membrane reactors. Of critical importance to modeling the properties of electrochemical ceramics, and developing new materials with improved performance, is a strong understanding of electronic structure. Since most electrochemical ceramics possess complex intermediate-length scale order, their properties often defy explanation when viewed from traditional paradigms invoking localized or collective viewpoints of electronic structure. In order to gain a more complete understanding of electronic structure in electrochemical ceramics, we propose to measure the populations of localized and delocalized electrons in transition metal perovskites having general composition LaSrCoFe oxides (LSCF) using a novel high-sensitivity Faraday balance. These measurements will be used to interpret parallel studies of electrochemical properties, including electron transport, ionic defect structure, chemical expansion and stress, and catalytic activity. In addition, the PI is currently developing a new program of undergraduate laboratory experiments that integrate research and teaching. This program provides undergraduates with formal opportunities to contribute to Ph.D.-level research in modern growth areas of chemical engineering, producing real data that will be published (not just put into a lab report). In this way research and undergraduate education are on the same track, with a complementary agenda. The proposed project will contribute one experiment to this educational program, which is linked (and feeds directly into) our research program in electrochemical ceramics. Students will screen new materials for electronic structure using high-temperature magnetic susceptibility measurements and Taguchi analysis methods. %%% This project will contribute broadly to our understanding of electronic structure in complex materials. The results are of general interest to all branches of materials science, including solid-state electrochemistry, electronic materials, ceramics, as well as inorganic chemistry and physics. This project will also provide specific information about electronic structure in one class of materials, of immediate value to workers developing reaction/separation membranes and solid-oxide fuel cells. The principal investigator has 8 years academic and 4 years industrial experience in this field, bringing a strong mix of fundamental and practical perspectives. This work is highly original, and contributes several novel advances to proven experimental techniques. The experimental plan is well organized, and the proposing institution has a world-class infrastructure for work in this cross-disciplinary field. In addition, the career development plan of the PI will help establish a strong fundamental research and educational program in a new, exciting, area of technology. This program will not only educate individual scientists in its field, but will also tightly integrate research and teaching in a way that benefits both, and opens new opportunities for undergraduates (many of whom, at CWRU, are women and minorities) to participate in cutting-edge research on a broad scale. This approach provides a new template for teaching that other higher-educational institutions may benefit from. Knowledge gained from both research and educational development will be disseminated broadly through the literature, and directly through strong ties of the PI to industry and the American Society of Engineering Education.