Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-25T00:35:33.685Z Has data issue: false hasContentIssue false

Composition-Morphology-Property Relations For Giant Magnetoresistance Multilayers Grown By RF Diode Sputtering

Published online by Cambridge University Press:  21 March 2011

W. Zou
Affiliation:
Department of Materials Science and EngineeringUniversity of Virginia, Charlottesville, VA 22903
H.N.G. Wadley
Affiliation:
Department of Materials Science and EngineeringUniversity of Virginia, Charlottesville, VA 22903
X.W. Zhou
Affiliation:
Department of Materials Science and EngineeringUniversity of Virginia, Charlottesville, VA 22903
R.A. Johnson
Affiliation:
Department of Materials Science and EngineeringUniversity of Virginia, Charlottesville, VA 22903
D. Brownell
Affiliation:
Nonvolatile Electronics, Inc. Eden Prairie, MN 55344
Get access

Abstract

A series of experiments have been conducted to evaluate the magnetotransport properties of RF diode sputter deposited giant magnetoresistive (GMR) multilayers with either copper or copper-silver-gold nonferromagnetic (NFM) conducting layers. The study revealed that RF diode deposited multilayers utilizing Cu80Ag15Au5 as the NFM conducting layer posses significantly superior giant magnetoresistance to otherwise identical device architectures that used pure copper as the NFM conducting layer. To explore the origin of this effect, copper and Cu80Ag15Au5 films of varying thickness have been grown under identical deposition conditions and their surface morphology and roughness investigated. Atomic force microscopy revealed significant roughness and the presence of many pinholes in thin pure copper films. The surface roughness of the Cu80Ag15Au5 layers was found to be much less than that of pure copper, and the alloying eliminated the formation of pinholes. Molecular statics estimates of activation barriers indicated that both silver and gold have significantly higher mobilities than copper atoms on a flat copper surface. However, gold is found to be incorporated in the lattice whereas silver tends to segregate (and concentrate) upon the free surface, enhancing its potency as a surfactant. The atomic scale mechanism responsible for silver's surface flattening effect has been explored.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Levy, P. M., J. Magn. Magn. Mater., 140–144, 485(1995).10.1016/0304-8853(94)00587-7Google Scholar
2. Kools, J.C. S., J. Appl. Phys. 77, 2993 (1995).Google Scholar
3. Daughton, J., Bade, P.A., Jenson, M.L., and Rahmati, M., IEEE Trans. Magn., Vol.28, No.5, Sept. 1992.Google Scholar
4. Prinz, G. A., Science 282, 1660(1998).Google Scholar
5. Dieny, B.et al. J. Appl. Phys. 69 (8), 15, P. 47744779, April 1991.10.1063/1.348252Google Scholar
6. Egelhoff, W. F. Jr, Chen, P. J., Powell, C. J., Stiles, M.D., and McMichael, R. D., J. Appl. Phys. 79 (5), March 1996.Google Scholar
7. Egelhoff, W. F.et al. J. Appl. Phys. 82 (12), 15 December 1997.Google Scholar
8. Zou, W., Wadley, H.N.G.et al., Prepared for J. Vacuum Science and Technology.Google Scholar
9. Wadley, H.N.G., Zhou, X., Johnson, R.A., Mechanisms, Models, and Methods of Vapor Deposition, Progress in Materials Science, In Press, 2001.Google Scholar
10. Johnson, R.A., Phys. Rev. 39, 12554, 1989.10.1103/PhysRevB.39.12554Google Scholar