Tantalum oxide as an alternative low height tunnel barrier in magnetic junctions

Rottla¨nder, P.; Hehn, M.; Lenoble, O.; Schuhl, A.
May 2001
Applied Physics Letters;5/21/2001, Vol. 78 Issue 21, p3274
Academic Journal
Magnetic tunnel junctions with a barrier of tantalum oxide were prepared by plasma oxidation of sputter-deposited tantalum. They show magnetoresistance ratios of 2.5% at room temperature and 4% at low temperatures. The material exhibits low barrier heights of ∼0.4 eV. This makes it possible to substantially increase the barrier thickness, compared to a barrier of aluminum oxide. The resulting decrease of coupling between the ferromagnetic layers is easily seen. Tantalum oxide appears to be a candidate for use as a tunnel barrier of spin-dependent tunneling devices. © 2001 American Institute of Physics.


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