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Effects of Interface Intermixing on the Magnetoresistance of Spin Valves with Uncoupled Co-Layers

Published online by Cambridge University Press:  15 February 2011

M.M.H. Willekens
Affiliation:
Eindhoven University of Technology, P.O.Box 513, 5600 MB, The Netherlands.
TH.G.S.M. Rijks
Affiliation:
Eindhoven University of Technology, P.O.Box 513, 5600 MB, The Netherlands. Philips Research Laboratories, Prof Holstlaan 4, 5656 AA Eindhoven, The Netherlands.
H.J.M. Swagten
Affiliation:
Eindhoven University of Technology, P.O.Box 513, 5600 MB, The Netherlands.
W.J.M. De Jonge
Affiliation:
Eindhoven University of Technology, P.O.Box 513, 5600 MB, The Netherlands.
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Abstract

We have studied the effect of an artificially intermixed region grown at the interfaces of Co/Cu spin valves with uncoupled layers. Two different structures are used: exchange-biased spin valves and engineered spin valves in which two layers are antiferromagnetically coupled and a third layer, on top of this system, is not coupled to the other two. It is shown that structural effects, induced by variation of the deposition parameters and by the intermixing can play an important role. Since the present study uses sputtered layers an intrinsic initial intermixing of 4-5Å is already present. For both types of spin valves Gp, ΔG and ΔR/R all show a gradual decrease when the nominal thickness of the total intermixed region is enlarged from 0 to 36Å. Also when the initial degree of intermixing is decreased by sputtering at higher Arpressure, Gp, ΔG and ΔR/R still show a gradual decrease as a function of intermixed layer thickness. Combined with the fact that there is no difference between an intermixed region of thickness t at one Co/Cu interface or intermixed regions of thickness t/2 at two interfaces, this indicates that the electron scattering in the intermixed region is predominantly spin independent, although this region preserves a magnetic moment.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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References

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