Hostname: page-component-77c89778f8-cnmwb Total loading time: 0 Render date: 2024-07-20T18:45:26.132Z Has data issue: false hasContentIssue false

SEMPA Studies of Exchange Coupling in Magnetic Multilayers

Published online by Cambridge University Press:  29 November 2013

Get access

Extract

In the late 1980s, a number of exciting yet puzzling observations resulted from experiments investigating the coupling between two ferromagnetic layers separated by a nonferromagnetic spacer layer. A pioneering experiment by Grünberg et al. showed that Fe layers separated by a thin Cr spacer aligned with antiparallel magnetization, but with Au as the spacer layer, a parallel alignment occurred. The long-range magnetic dipole from each layer would tend to explain antiparallel alignment; small pinholes in the spacer layer would produce parallel alignment. Alternatively, the layers might be coupled through the spacer-layer conduction electrons by the Ruder man-Kittel-Kasuya-Yosida (RKKY) effect. This was expected to produce an oscillation in coupling as the spacer thickness increased, that is, an oscillation between parallel and antiparallel alignment. Oscillatory coupling was first observed by Parkin et al. Researchers had also found that, at spacer thicknesses where antiparallel alignment occurred, the Fe/Cr/Fe system can exhibit a giant magnetoresistance (GMR) effect, that is, an anomalously large change in resistance when a magnetic field is applied. The potential technological importance of the GMR effect to magnetic sensing and magnetic information storage added further impetus to the already rapidly growing area of research in magnetic multilayers.

Type
Magnetism on a Microscopic Scale
Copyright
Copyright © Materials Research Society 1995

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

1.Grünberg, P., Schreiber, R., Pang, Y., Brodsky, M.B., and Sowers, H., Phys. Rev. Lett. 57 (1986) p. 2442.CrossRefGoogle Scholar
2.Parkin, S.S.P., More, N., and Roche, K.P., Phys. Rev. Lett. 64 (1990) p. 2304.CrossRefGoogle Scholar
3.Baibich, M.N., Broto, J.M., Fert, A., Van Dau, F. Nguyen, Petroff, F., Etienne, P., Creuzet, G., Friederich, A., and Chazelas, J., Phys. Rev. Lett. 61 (1988) p. 2472.CrossRefGoogle Scholar
4.Binasch, G., Grünberg, P., Saurenbach, F., and Zinn, W., Phys. Rev. B 39 (1989) p. 4828.CrossRefGoogle Scholar
5.Pierce, D.T., Unguris, J., and Celotta, R.J., in Ultrathin Magnetic Structures II, edited by Heinrich, B. and Bland, J.A.C. (Springer-Verlag, Berlin, 1994) p. 117.Google Scholar
6.Scheinfein, M.R., Unguris, J., Kelley, M.H., Pierce, D.T., and Celotta, R.J., Rev. Sci. Instrum. 61 (1990) p. 2501.CrossRefGoogle Scholar
7. Fe whiskers were provided by Simon Fraser University under an operating grant from the National Science and Engineering Research Council of Canada.Google Scholar
8.Unguris, J., Celotta, R.J., and Pierce, D.T., Phys. Rev. Lett. 67 (1) (1991) p. 140.CrossRefGoogle Scholar
9.Stroscio, J.A., Pierce, D.T., and Dragoset, R.A., Phys. Rev. Lett. 70 (1993) p. 3615.CrossRefGoogle Scholar
10.Pierce, D.T., Stroscio, J.A., Unguris, J., and Celotta, R.J., Phys. Rev. B 49 (1994) p. 14,564.CrossRefGoogle Scholar
11.Bruno, P. and Chappert, L., Phys. Rev. Lett. 67 (1991) p. 1602.CrossRefGoogle Scholar
12.Stiles, M.D., Phys. Rev. B 48 (1993) p. 7238.CrossRefGoogle Scholar
13.Hathaway, K.B., in Ultrathin Magnetic Structures II, edited by Heinrich, B. and Bland, J.A.C. (Springer-Verlag, Berlin, 1994), p. 4581, and references therein.CrossRefGoogle Scholar
14.Unguris, J., Celotta, R.J., and Pierce, D.T., Phys. Rev. Lett. 69 (1992) p. 1125.CrossRefGoogle Scholar
15.Unguris, J., Celotta, R.J., and Pierce, D.T., J. Magn. Mat. 127 (1993) p. 205.CrossRefGoogle Scholar
16.Unguris, J., Celotta, R.J., and Pierce, D.T., J. Appl. Phys. 75 (1994) p. 6437.CrossRefGoogle Scholar