March 19, 2003
FRONTIERS IN MATERIALS SCIENCE
VINSE COLLOQUIUM SERIES
Dr. Chris Palmstrom
Chemical Engineering and Materials Science
University of Minnesota
"Growth and Characterization of Ferromagnetic Metal/Compound Semiconductor Heterostructures: a Path Towards Spintronics"
Abstract. A key element to developing �spintronic� devices is the ability to electrically inject spin polarized electrons or holes from a magnetic material into an otherwise unpolarized semiconductor. Ideal interfaces are required to minimize spin randomizing scattering at the interface magnetic/semiconductor interface. This talk will emphasize the growth and characterization of epitaxial ferromagnetic Fe1-xCox, Ni2MnGa, Ni2MnIn and Ni2MnGe films grown by molecular beam epitaxy on Ga1-xInxAs. Structural characterization includes in-situ reflection high energy electron diffraction, low energy electron diffraction, scanning tunneling microscopy and x-ray photoelectron spectroscopy as well as ex-situ x-ray diffraction, Rutherford backscattering and cross-sectional TEM. The influence of the interface on the structural and magnetic properties will be discussed as well as issues in determining the spin polarized transport across the ferromagnet/semiconductor interface.