Magnetoresistance studies on Co/AlOX/Au and Co/AlOX/Ni/Au tunnel structures

Research output: Contribution to journalArticle


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.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Condensed Matter Physics


  • nickel, magnetisation, tunnelling magnetoresistance, magnetic thin films, gold, ferromagnetic materials, polarisation, electron spin, cobalt, aluminium compounds, band structure
Original languageEnglish
Article number203107
JournalApplied Physics Letters
Issue number20
Publication statusPublished - 2008
Publication categoryResearch