****Technical Abstract**** Complex oxide materials have proven to be an extraordinary platform for discovery of new and useful physical phenomena. Assembling these materials into artificial heterostructures provides a plethora of further opportunities, both for discovery of new science, and for applications in areas such as ferroelectric RAM, fuel cells, and spintronics. However, in order to fully exploit these materials some serious open issues must be resolved, particularly with respect to interfacial strain and defects. The goal of this project is to achieve exactly this, using cobalt oxides as model systems to understand the interplay between strain state, oxygen vacancy formation and ordering, and interface magnetism/electronic transport. Specific opportunities include the use of strain-control over oxygen defects to precisely engineer interfacial magnetic and electronic properties, and the possibility of synthesizing defect-free materials to probe new physics recently predicted by theory. The research will have impact well beyond the immediate disciplines in which it is performed, due to its relevance to emerging technologies, the exceptional educational opportunities provided to students, and inclusion of under-represented groups. Outreach to the public will also be achieved via development of an interactive presentation for the Properties of Matter module in the Minneapolis Public School System, impacting hundreds of 8th grade students.
Complex oxides, formed by bonding atoms of multiple metallic elements with oxygen, are a set of materials that display extraordinary diversity in physical and chemical properties, yielding some of the most important discoveries in physics. The recently recognized ability to incorporate these materials into artificial structures where multiple oxides are laminated together, with atomic-scale precision, provides a means to fully exploit their properties in a wide variety of applications. These include zero boot-up time memory, clean-burning fuel cells, and low power consumption high-speed electronics. However, critical unsolved issues hinder progress in this area, particularly the formation of unwanted defects associated with missing oxygen atoms. In this project a specific set of complex oxide materials are being used to understand what factors control the formation and arrangement of these defects, the influence they have on properties, and the means by which we can control them. The ultimate goal is to be able to precisely control electronic and magnetic behavior at oxide interfaces in order to fully exploit their unique properties in a wide variety of new devices. The research will have broad impact due to its relevance to emerging technologies, the exceptional educational opportunities provided to students, and inclusion of under-represented groups. Outreach to the public will also be achieved via development of an interactive presentation for the Properties of Matter module in the Minneapolis Public School System, impacting hundreds of 8th grade students.
