NIRT: Epitaxial Magnetic Oxide Structures for Nanoscale Spin Devices

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

0210449 Eom This proposal was received in response to the Nanoscale Science and Engineering Initiative, Program Solicitation NSF 01-157, in the NIRT category. The proposal focuses on understanding intrinsic phenomena governing spin transport at the nanoscale, and the development of new methods for its manipulation for future spin-controlled, magneto-electronic, devices. It addresses one of the most exciting aspects of current research on next-generation electronic devices: the manipulation of spin, rather than only electrical charge. The advantages of these magnetoelectronic devices include nonvolatility, faster switching in static memory elements, and higher density due to a simpler device structure. These issues become even more important as technology drives device sizes toward the nanoscale, where new fundamental physical effects emerge that alter spin transport, as well as high-frequency dynamics and switching times. An understanding of these issues at the nanoscale requires single-crystal magnetic heterostructures with atomically-sharp interfaces, patterned to nanometer dimensions. This proposal probes nanoscale spin transport phenomena in epitaxial magnetic oxide nanostructures grown with atomic-layer control, whose magnetic, electronic, and interfacial properties are tuned at will. Layers with defined electronic, magnetic, and morphological characteristics positioned with atomic-layer control in epitaxial systems are used to address crucial fundamental questions in magnetic nanostructures. This research program consists of 1) design, growth, and characterization of epitaxial magnetic oxide heterostructures with atomic layer control by pulsed laser deposition with in-situ real-time structural analysis 2) high-resolution and analytical TEM to determine atomic structure and electronic properties of the interfaces; 3) nanoscale patterning of novel magnetic heterostructures below 50 nm; 4) scanning probe measurements of topography and local electronic properties; 5) education and outreach efforts with a focus on introducing young people to modern, multidisciplinary science and technology, using the research direction as a vehicle. The multidisciplinary, multiuniversity/industry team consists of members working in Materials Science, Physics, Electrical Engineering, and device development. Research, education, and outreach all follow the theme of nanoscale structures, novel phenomena, and spin transport control. This work will build a scientific foundation for the understanding of new phenomena in nanoscale spin-controlled devices. The PIs industrial and multidisciplinary interactions will be very beneficial in advancing research as well as in educating students. This study will also provide fundamental guidelines in the atomic-scale control of nanoscale systems such as ferroelectrics and oxide-semiconductor integration that are important for next-generation technology.