https://doi.org/10.1051/epjap:2005080
Effect of ion irradiation on the characteristics of magnetic tunnel junctions
1
MESA Institute for Nanotechnology,
University of Twente, 7500 AE Enschede, The Netherlands
2
Francis Bitter Magnet Lab, MIT, 170 Albany Street, Cambridge, MA02139, USA
3
Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005, Orissa, India
4
Nuclear
Science Centre, Aruna Asaf Ali Marg, New Delhi 110 067, India
Corresponding author: T.Banerjee@ewi.utwente.nl
Received:
5
May
2005
Revised:
19
July
2005
Accepted:
20
July
2005
Published online:
26
October
2005
The effect of disorder caused by MeV heavy ion
irradiation on the tunnel magnetoresistance (TMR) of magnetic
tunnel junctions is investigated. Two types of tunnel junctions,
viz. Co/Al2O3/Ni80Fe20 and Co/Gd-doped
Al2O3/Ni80Fe20 are studied. Upon 70 MeV Si ion
irradiation at a fluence of 
ions/cm2, the undoped
junctions show relatively small but irreversible change, while the
Gd-doped junctions show a huge reduction, in TMR. In both cases
junctions were completely destroyed by 200 MeV Ag ion irradiation
at a fluence of 
ions/cm2. The results are
attributed to the modification of the barrier and the neighboring
interfaces caused by the high energy density deposited by incident
ions.
PACS: 61.80.Jh – Ion radiation effects / 85.30.Mn – Junction breakdown and tunneling devices (including resonance tunneling devices) / 85.70.Kh – Magnetic thin film devices: magnetic heads (magnetoresistive, inductive, etc.); domain-motion devices, etc.
© EDP Sciences, 2005
