Journal article · Conference paper
Hybrid Spintronic Structures With Magnetic Oxides and Heusler Alloys
Department of Micro- and Nanotechnology, Technical University of Denmark1
Magnetic Systems Group, LabChip Section, Department of Micro- and Nanotechnology, Technical University of Denmark2
LabChip Section, Department of Micro- and Nanotechnology, Technical University of Denmark3
Quantum Physics and Information Technology, Department of Physics, Technical University of Denmark4
Department of Physics, Technical University of Denmark5
Risø National Laboratory for Sustainable Energy, Technical University of Denmark6
Hybrid spintronic structures, integrating half-metallic magnetic oxides and Heusler alloys with their predicted high spin polarization, are important for the development of second-generation spintronics with high-efficient spin injection. We have synthesized epitaxial magnetic oxide Fe3O4 on GaAs(100) and the unit cell of the Fe3O4 was found to be rotated by 45 degrees to match the gallium arsenide GaAs.
The films were found to have a bulk-like moment down to 3-4 nm and a low coercivity indicating a high-quality magnetic interface. The magnetization hysteresis loops of the ultrathin films are controlled by uniaxial magnetic anisotropy. The dynamic response of the sample shows a heavily damped precessional response to the applied field pulses.
In the Heusler alloy system of Co-2 MnGa on GaAs, we found that the magnetic moment was reduced for thicknesses down to 10 nm, which may account for the lower than expected spin-injection efficiency from the spin-light-emitting diode structures. Using the element-specific technique of X-ray magnetic circular dichroism (XMCD), the reduced spin moments were found to originate from the Mn rather than the Co atoms, and the improvement of the interface is thus needed to increase the spin injection efficiency in this system.
Further studies of the I-Vcharacteristics of Fe3O4/GaAs(100) and Fe3O4/MgO/GaAs(100) show that the Fe3O4-based spintronic structures have a well-defined Schottky or tunneling barrier of moderate barrier height, which is encouraging for high-efficient spin injection.
| Language: | English |
|---|---|
| Publisher: | IEEE |
| Year: | 2008 |
| Pages: | 2959-2965 |
| Proceedings: | 2008 International Magnetics Conference |
| ISSN: | 19410069 and 00189464 |
| Types: | Journal article and Conference paper |
| DOI: | 10.1109/TMAG.2008.2002188 |
| ORCIDs: | Damsgaard, Christian Danvad and 0000-0002-7963-3649 |
Gallium arsenide (GaAs) Heusler alloys magnetic oxides magnetite molecular-beam epitaxy spintronics ultra-thin films
Co<sub>2</sub>MnGa Coercive force Fe<sub>3</sub>O<sub>4</sub>-MgO-GaAs GaAs Gallium arsenide Iron Magnetic anisotropy Magnetic films Magnetization Magnetoelectronics Perpendicular magnetic anisotropy Polarization Schottky barrier Schottky barriers Spin polarized transport X-ray magnetic circular dichroism XMCD cobalt alloys coercive force coercivity epitaxial magnetic oxide gallium alloys gallium arsenide hybrid spintronic structures interface magnetism iron compounds magnesium compounds magnetic anisotropy magnetic circular dichroism magnetic epitaxial layers magnetic hysteresis magnetic interface magnetic moment magnetic moments magnetic multilayers magnetization hysteresis loops magnetoelectronics manganese alloys spin injection spin moments spin polarised transport spin polarization spin-light-emitting diode structures tunneling barrier ultrathin films uniaxial magnetic anisotropy
