Epitaxial Ferromagnet/Semiconductor Hybrids for Spintronics

Lennart-Knud Liefeith, Rajkiran Tholapi, Christian Heyn, Taras Slobodskyy, and Wolfgang Hansen

The epitaxial growth of iron and the Heusler alloys Ni2MnIn, Ni2MnGa and Ni2MnGe on semiconductor heterostructures is studied. With molecular-beam epitaxy we are able to grow ultra-clean GaAs/AlGaAs and various InAs heterostructures with high electron mobilities. The composition of the metallic layers, intermixing effects, and the formation of dislocations will be studied in situ by Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED). Further characterizations will be performed ex situ by atomic-force microscopy, magnetic-force microscopy, X-ray diffraction and transmission electron microscopy. The spin polarization will be determined by point-contact Andreev spectroscopy.

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