Thickness dependence and the role of spin transfer torque in nonlinear giant magnetoresistance of permalloy dual spin valves

Banerjee, N. and Aziz, A. and Ali, M. and Robinson, J. W. A. and Hickey, B. J. and Blamire, M. G. (2010) Thickness dependence and the role of spin transfer torque in nonlinear giant magnetoresistance of permalloy dual spin valves. Physical review B, 82 (22). ISSN 1098-0121

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Abstract

The recent discovery of nonlinear current-dependent magnetoresistance in dual spin valve devices [A. Aziz, O. P. Wessely, M. Ali, D. M. Edwards, C. H. Marrows, B. J. Hickey, and M. G. Blamire, Phys. Rev. Lett. 103, 237203 (2009)] opens up the possibility for distinct physics which extends the standard model of giant magnetoresistance. When the outer ferromagnetic layers of a dual spin valve are antiparallel, the resulting accumulation of spin in the middle ferromagnetic layer strongly modifies its bulk and interfacial spin asymmetry and resistance. Here, we report experimental evidence of the role of bulk spin accumulation in this nonlinear effect and show that interfacial spin accumulation alone cannot account for the observed dependence of the effect on the thickness of the middle ferromagnetic layer. It is also shown that spin torque acting on the middle ferromagnetic layer combined with the nonlinear effect might be useful in understanding the dynamical features associated with the nonlinear behavior.

Item Type:
Journal Article
Journal or Publication Title:
Physical review B
Additional Information:
© 2010 The American Physical Society
Subjects:
ID Code:
63530
Deposited By:
Deposited On:
19 Apr 2013 10:16
Refereed?:
Yes
Published?:
Published
Last Modified:
02 Jul 2020 01:04