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

Liu, Ruisheng LU ; Canali, C. M.; Samuelson, Lars LU and Pettersson, H (2008) In Applied Physics Letters 93(20).
Abstract
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... (More)
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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
nickel, magnetisation, tunnelling magnetoresistance, magnetic thin films, gold, ferromagnetic materials, polarisation, electron spin, cobalt, aluminium compounds, band structure
in
Applied Physics Letters
volume
93
issue
20
publisher
American Institute of Physics
external identifiers
  • wos:000261141400050
  • scopus:56849094689
ISSN
0003-6951
DOI
10.1063/1.3000614
language
English
LU publication?
yes
id
6abc517b-1ed4-4d5c-bfe5-4bacadadd742 (old id 1307991)
date added to LUP
2009-03-19 13:31:51
date last changed
2017-01-01 05:09:42
@article{6abc517b-1ed4-4d5c-bfe5-4bacadadd742,
  abstract     = {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.},
  articleno    = {203107},
  author       = {Liu, Ruisheng and Canali, C. M. and Samuelson, Lars and Pettersson, H},
  issn         = {0003-6951},
  keyword      = {nickel,magnetisation,tunnelling magnetoresistance,magnetic thin films,gold,ferromagnetic materials,polarisation,electron spin,cobalt,aluminium compounds,band structure},
  language     = {eng},
  number       = {20},
  publisher    = {American Institute of Physics},
  series       = {Applied Physics Letters},
  title        = {Magnetoresistance studies on Co/AlOX/Au and Co/AlOX/Ni/Au tunnel structures},
  url          = {http://dx.doi.org/10.1063/1.3000614},
  volume       = {93},
  year         = {2008},
}