Phys. Rev. Lett. Phys. Rev. A Phys. Rev. B Phys. Rev. C Phys. Rev. D Phys. Rev. E Phys. Rev. ST AB Rev. Mod. Phys. Phys. Rev. (Series I) Phys. Rev. Volume: Page/Article:

Phys. Rev. Lett. 64, 2304–2307 (1990)

[Issue 19 – 7 May 1990 ]

[ Previous article | Next article | Issue 19 contents ]

Oscillations in exchange coupling and magnetoresistance in metallic superlattice structures: Co/Ru, Co/Cr, and Fe/Cr

S. S. P. Parkin, N. More, and K. P. Roche

IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099

We report the discovery of antiferromagnetic interlayer exchange coupling and enhanced saturation magnetoresistance in two new metallic superlattice systems, Co/Cr and Co/Ru. In these systems and in Fe/Cr superlattices both the magnitude of the interlayer magnetic exchange coupling and the saturation magnetoresistance are found to oscillate with the Cr or Ru spacer layer thickness with a period ranging from 12 Å in Co/Ru to ~=18–21 Å in the Fe/Cr and Co/Cr systems.

©1990 The American Physical Society

URL: http://link.aps.org/abstract/PRL/v64/p2304
DOI: 10.1103/PhysRevLett.64.2304
PACS: 75.50.Rr, 72.15.Gd, 75.70.Cn

[ Previous article | Next article | Issue 19 contents ]

References

1. M. N. Baibich, J. M. Broto, A. Fert, F. Nguyen van Dau, F. Petroff, P. Etienne, G. Creuzet, A. Friederich and J. Chazelas, Phys. Rev. Lett. 61, 2472 (1988).
2. G. Binasch, P. Grunberg, F. Saurenbach and W. Zinn, Phys. Rev. B 39, 4828 (1989).
3. P. Grunberg, R. Schreiber, Y. Pang, M. B. Brodsky and H. Sowers, Phys. Rev. Lett. 57, 2442 (1986).
4. C. Carbone and S. F. Alvarado, Phys. Rev. B 36, 2443 (1987).
5. S. S. P. Parkin, G. Chien, N. More, and K. P. Roche (unpublished).
6. The resistance of the samples was measured using a four-probe low-frequency ac lock-in technique with spring-loaded pressure contacts. All the magnetoresistance data presented in this paper were measured at 4.5 K. The saturation magnetoresistance Delta R / R is defined as the ratio of the difference between the peak in resistance of the sample at low field and the resistance at high field divided by the value at high field. For samples with thick spacer layers of Cr or Ru the peak of the resistance curve at low fields was shifted from zero field and displayed hysteresis. Magnetization data were measured using vibration sample and SQUID magnetometry. The saturation field H_s was defined as the field at which the resistance or magnetization curve first deviates from the high-field slope.
7. F. Nguyen van Dau, A. Fert, P. Etienne, M. N. Baibich, J. M. Broto, J. Chazelas, G. Creuzet, A. Friederich, S. Hadjoudj, H. Hurdequint, J. P. Redoules, and J. Massies,, J. Phys. (Paris) Colloq. 49, C8-1633 (1988) [ INSPEC].
8. S. S. P. Parkin, S. Fan, N. More, K. P. Roche, A. Mansour, and G. P. Felcher (unpublished).
9. Y. Yafet, J. Appl. Phys. 61, 4058 (1987) [ SPIN][ INSPEC].
10. Note that while data are included in Fig. 3 for a Ru layer thickness of 1 Å we assume that at this thickness the Ru layer is discontinuous so that the Co layers are directly exchange coupled.
11. See, for example, K. Moorjani and J. M. D. Coey, Magnetic Glasses (Elsevier, Amsterdam, 1984).

[ Previous article | Next article | Issue 19 contents ]