IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Magnetic Interfaces and Nanostructures Tuesday Sessions
       Session MI+EL-TuA

Paper MI+EL-TuA4
Magnetotransport in Digital Ferromagnetic Heterostructures

Tuesday, October 30, 2001, 3:00 pm, Room 110

Session: Spintronics II: Spin Injection & Transport
Presenter: T.C. Kreutz, University of California, Santa Barbara
Authors: T.C. Kreutz, University of California, Santa Barbara
G. Zanelatto, University of California, Santa Barbara
R. Kawakami, University of California, Santa Barbara
E. Johnston-Halperin, University of California, Santa Barbara
E.G. Gwinn, University of California, Santa Barbara
A.C. Gossard, University of California, Santa Barbara
D.D. Awschalom, University of California, Santa Barbara
Correspondent: Click to Email
Recent studies of digital ferromagnetic heterostructures (DFH), in which fractional monolayers (ML) of MnAs alternate with interlayers of low temperature (LT) GaAs, have shown that the Curie temperature, Tc, is sensitive to the separation between MnAs sheets.@footnote 1@ We report studies of in-plane magnetotransport in these structures, for Be-doped and nominally undoped LT GaAs interlayers with thicknesses from 10 to 40 ML. For undoped DFH grown at 260 C, structures with 10 ML interlayers show an anom alous Hall effect, while structures with 20 and 40 ML interlayers show only the ordinary Hall effect. The decrease in Tc with increasing interlayer thickness is accompanied by a decrease in the Hall carrier density and mobility. The magnetoresistance of the 10 ML sample has a similar field dependence to bulk GaMnAs. The 20 and 40 ML magnetoresistances are qualitatively different. Effects of Be doping are also considered for DFH samples.. @FootnoteText@ @footnote 1@ R.K. Kawakami, et al APL 2379 (2000).