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HL: Fachverband Halbleiterphysik
HL 20: Innovative Materials
HL 20.5: Talk
Monday, March 14, 2011, 15:30–15:45, POT 06
Molecular beam epitaxy of Heusler alloys on InAs heterostructures — •Boris Landgraf, Sascha Bohse, Christian Heyn, and Wolfgang Hansen — Institut für Angewandte Physik, Universität Hamburg, 20355 Hamburg, Germany
The injection of highly spin-polarized electrons from ferromagnets into low-dimensional semiconductor systems is important for spintronic applications. The main problem encountered when building such spintronic devices is that spin-polarization of electrons gets lost at the metal/semiconductor interface. We investigate epitaxial growth as well as structural, magnetical, and electrical properties of Heusler/semiconductor hybrid systems. In particular, we focus on Ni2MnIn Heusler grown on InAs(001) as well as on modulation-doped InGaAs/InAs/InGaAs heterostructures. One previous finding [1] with this hybrid system reveals that As diffuses from InAs into the Heusler film and forms a significant intermixing layer. We pursue two possibilities to overcome this problem. One is the growth of a MgO diffusion-barrier to avoid intermixing at the interface. Corresponding data will be discussed. Another solution is the use of other Heusler candidates. For that reason, we run a new metal molecular beam epitaxy (MBE) chamber in our laboratory, which is connected with a commercial III/V semiconductor MBE via an in-vacuo transfer system. This MBE chamber enables the growth of MgO as well as of different Heusler alloys.
[1] A. Zolotaryov et al., J. Cryst. Growth 2397–2404, 311 (2009)