Magnetoresistance studies on Co/AlOX/Au and Co/AlOX/Ni/Au tunnel structures
Författare
Summary, in English
We report on magnetoresistance (MR) studies on Co/AlOX/Au and Co/AlOX/Ni/Au magnetic tunnel junctions. In spite of the fact that the difference between the two samples is merely a 3 nm thick Ni layer, there is a sharp contrast in MR behavior indicating that the electronic structure at the interface between the ferromagnetic electrodes and the insulating barrier dominates the MR signal. The former sample exhibits a clear tunneling anisotropic MR (TAMR), with the characteristic correlation between resistance and current direction, in contrast to the latter sample which displays a conventional tunneling MR (TMR) dominated by the relative orientation between the magnetization directions of the two electrodes. In addition, the TAMR has a much stronger temperature dependence than the TMR, indicating a much faster drop-off of the tunneling density of states anisotropy than the tunneling electron spin polarization with increasing temperature. Finally, we propose a possible simple way to distinguish TAMR from normal TMR by measuring the resistance of the device at different angles of the external magnetic field.
Avdelning/ar
Publiceringsår
2008
Språk
Engelska
Publikation/Tidskrift/Serie
Applied Physics Letters
Volym
93
Issue
20
Dokumenttyp
Artikel i tidskrift
Förlag
American Institute of Physics (AIP)
Ämne
- Condensed Matter Physics
Nyckelord
- nickel
- magnetisation
- tunnelling magnetoresistance
- magnetic thin films
- gold
- ferromagnetic materials
- polarisation
- electron spin
- cobalt
- aluminium compounds
- band structure
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0003-6951