MRS Bulletin

Technical Feature

Technical Feature

Combinatorial Investigation of Spintronic Materials

Y. Matsumoto, H. Koinuma, T. Hasegawa, I. Takeuchi, F. Tsui and Young K. Yoo

Abstract

High-throughput synthesis and characterization techniques have been effective in discovering new materials and performing rapid mapping of phase diagrams. The application of the combinatorial strategy to explore doped transition-metal oxides has led to the discovery of a transparent room-temperature ferromagnetic oxide in Co-doped anatase TiO2. The discovery has triggered a wave of studies into other metal oxide systems in pursuit of diluted magnetic semiconductors. In this article, we describe recent combinatorial studies of magnetic transition-metal oxides, germanium-based magnetic semiconductors, and Heusler alloys.

Keywords

  • combinatorial thin-film technology;
  • germanium;
  • Heusler alloys;
  • magnetic semiconductors;
  • oxides;
  • spin-polarized materials;
  • spintronics

Yuji Matsumoto is a research associate in the Frontier Collaborative Research Center at the Tokyo Institute of Technology. His research interests include surface chemistry, nanostructures, and materials, and the development and application of combinatorial thin-film technology. He received his BS, MS, and PhD degrees in physical chemistry from the University of Tokyo. He has been working with H. Koinuma for more than five years. His current work on combinatorial materials research includes photocatalysts, phosphors, and superconducting, ferroelectric, and magnetic materials.

Matsumoto can be reached at the Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226 Japan; tel. 81–45–924–5314, fax 81–45–924–5875, and e-mail matsumoto@oxide.msl.titech.ac.jp.

Hideomi Koinuma is a professor and director of the Materials and Structures Laboratory at the Tokyo Institute of Technology. His interest in materials research began with polymer synthesis and characterization at the University of Tokyo, where he received his PhD degree in 1970. He returned to Tokyo after a two-year postdoctoral research position in chemical kinetics at Kansas University and then shifted his interests to amorphous silicon and other thin-film electronic materials. His current focus is on combinatorial nanotechnology for functional oxides. He founded the International Workshop on Oxide Electronics in 1995 and the Japan–U.S. Workshop on Combinatorial Materials Science and Technology in 2000.

Koinuma can be reached at the Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226 Japan; tel. 81–45–924–5314, fax 81–45–924–5875, and e-mail koinuma@oxide.rlem.titech.ac.jp.

Tetsuya Hasegawa is a professor in the Department of Chemistry at the University of Tokyo. His current research interest is combinatorial chemistry, especially high-throughput characterization of physical properties. He received his PhD degree in analytical chemistry from the University of Tokyo in 1985. After a postdoctoral research position at the University of Florida, he returned to Tokyo in 1986. Since then, he has devoted his research to solid-state chemistry and the materials science of superconducting and magnetic compounds with the aid of scanning probe microscopes.

Hasegawa can be reached at the Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226 Japan; tel. 81–45–924–5314, fax 81–45–924–5875, and e-mail hasegawa@chem.s.u-tokyo.ac.jp.

Ichiro Takeuchi is an assistant professor in the Department of Materials Science and Engineering and the Center for Superconductivity Research at the University of Maryland, College Park. His research interests include novel multilayer thin-film devices, scanning probe microscopes, and the development and application of combinatorial methodology for functional thin-film materials. He received his BS degree in physics from the California Institute of Technology in 1987 and his PhD degree in physics from the University of Maryland in 1996. He was a postdoctoral research fellow at Lawrence Berkeley National Laboratory from 1996 to 1999. He received the Office of Naval Research's Young Investigator Award in 2000 and the National Science Foundation's CAREER Award in 2001.

Takeuchi can be reached at the University of Maryland, Department of Materials and Nuclear Engineering, Building 90, College Park, MD 20742, USA; tel. 301–405–6809, fax 301–405–6327, and e-mail takeuchi@squid.umd.edu.

Frank Tsui is an associate professor of physics and a research associate professor of applied and materials science at the University of North Carolina at Chapel Hill. The focus of his research has been atomic-scale synthesis and characterization of magnetic heterostructures using molecular-beam epitaxy techniques. He received his BS degree in engineering physics from the University of California at Berkeley in 1984, and his MS (1987) and PhD (1992) degrees in physics from the University of Illinois at Urbana-Champaign. He was a Margaret and Herman Sokol postdoctoral fellow in the sciences at the University of Michigan. He then joined the faculty of the University of North Carolina in 1995 as an assistant professor of physics. He was a recipient of the National Science Foundation's Faculty Early Career Development Award.

Tsui can be reached at the University of North Carolina, Department of Physics and Astronomy, CB#3255, Chapel Hill, NC 27599, USA; tel. 919–962–0305, fax 919–962–0480, and e-mail ftsui@physics.unc.edu.

Young K. Yoo, Guest Editor for this issue of MRS Bulletin, is a vice president of research and development at Intematix Corp. in Moraga, Calif. Using combinatorial materials synthesis tools and high-throughput screening techniques, he has focused his research on continuous physical and structural phase mapping of complex oxide and metallic alloy systems. Since joining Intematix, he has been responsible for the design and development of new combinatorial thin-film deposition/screening tools and new materials discovery projects. His current research interests include dielectric materials, magnetic semiconductors, magnetic alloys, and hydrogen-storage materials. He received a BA degree in physics with honors from University of Chicago (1995) and a PhD in physics from the University of California at Berkeley (2000).

Yoo can be reached by e-mail at yyoo@intematix.com.

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