TITLE

Reduction of the spin-torque critical current by partially canceling the free layer demagnetization field

AUTHOR(S)
Liu, Luqiao; Moriyama, Takahiro; Ralph, D. C.; Buhrman, R. A.
PUB. DATE
March 2009
SOURCE
Applied Physics Letters;3/23/2009, Vol. 94 Issue 12, p122508
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
We significantly reduce the critical current Ic0 for the onset of spin torque switching of the free layer in nanometer-scale in-plane magnetized spin valves by partially cancelling its intrinsic demagnetization field through the utilization of Co/Ni multilayer free layers. The out-of-plane magnetic anisotropy arising from the Co/Ni interfaces reduces the effective demagnetization field (Heff) while not significantly affecting the thermal stability of the free layer. A zero-thermal-fluctuation critical current density Jc0∼2×106 A/cm2 is determined through both current ramp rate and nanosecond pulse measurements, and comparisons with large Heff control samples confirm that this strategy is efficient in substantially decreasing Ic0.
ACCESSION #
37259565

 

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