TECHNICAL: In this interdisciplinary project, PI plans to perform a combined experimental and theoretical study of a new complex compound alloy BaxSr1−xCo1−yFeyO3−ä (BSCF) with the ABO3 perovskite structure, which has a high potential for applications in energy conversion. The large number of prospective metal-metal compositions embedded in this structure and their diversity of properties provide a major opportunity for exploring and developing a new materials function for the next generation of fuel cell electrodes and membranes. It also represents an outstanding challenge for both experimental and computational studies as they face with the fact that these compounds are non-stoichiometric in oxygen content which gives many degrees of freedom in theoretical modeling and experimental analysis. To attack the problem, PI will use the state-of-the-art large scale parallel computer modeling based on the first-principles electronic structure calculations in conjunction with combinatorial growth techniques and a comprehensive range of characterization tools. PI will study, atomistically, the catalytic properties of BSCF, a new class of quite exotic magnetic alloys, including an interaction of an oxygen molecule with alloy surfaces, a mechanism of its reduction, transport through and along the electrode, and role of structural/impurity defects and material composition on the efficiency of the oxygen transport. Experimental studies will be closely coordinated with relevant theoretical/computational activities. This is a challenging high risk/high payoff, transformative project, which represents a preliminary work on largely untested and novel ideas; PI intends to optimize materials composition, to understand its properties, and to maximize its function of converting energy. If successful, this state-of-the-art study will yield two important breakthroughs: it will gain the fundamental understanding of the structure-property-function relationship in a series of new class of multi-component semi-metals and give a specific guidance for developing more efficient and compact devices. NON-TECHNICAL: New advanced materials are desperately needed for the sustainable 21st century and for new sources of ecologically clean energy. The new compound materials under study, BSCF, are extremely complex multicomponent magnetic alloys, which differ considerably from both traditional metals and oxides, and are yet to be synthesized, studied, and understood. In this project, PI plans to explore these novel advanced semi-metals baring in mind their potential use as cathodes of solid fuel cells for ecologically clean conversion of the chemical energy into electricity and new generation membranes for gas separation, in particular, green house CO2 gas in power plants. This may not only deliver a new material (or a class of new materials), but also open up new opportunities in materials design. This is of enormous technological importance and is expected to have a tremendous impact on energetics, economy and society. Even incremental knowledge to be obtained in this study that would allow us to determine the rate-determining steps in the course of the oxygen reduction on alloy surfaces and further transport across the material, will result in providing valuable guidance to developers and engineers on how to increase efficiency of existing fuel cell devices. Should the research be comprehensively fruitful, it will bring about a vastly new concept of converting energy, which will be based on the manipulation of the materials composition and materials by design.