Magnetotransport properties of magnetically soft spin-valve structures (invited)

• B. Dieny

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

• V. S. Speriosu

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

• S. Metin

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

• S. S. P. Parkin

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

• B. A. Gurney

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

• P. Baumgart

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

• D. R. Wilhoit

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

Abstract

The magnetic and magnetotransport properties of several series of sandwiches consisting of two ferromagnetic layers (Ni, Co, Ni80Fe20) separated by a noble metal (Cu, Ag, Au) are described. In order to vary the relative orientation of the magnetizations of the two ferromagnets, one of them was constrained by exchange anisotropy (e.g., NiFe/Fe50Mn50). The ferromagnetic layers are magnetically soft and not coupled antiparallel, giving very large changes of resistance at low fields. At room temperature relative changes ΔR/R of 4.1% in 10 Oe for Si/Ta 50 Å/NiFe 62 Å/Cu 22 Å/NiFe 40 Å/FeMn 70 Å/Ta 50 Å and 8.7% in 20 Oe has been obtained for a structure based on Co/Cu/Co layers. The magnetoresistance versus the thickness of the ferromagnetic layer shows a broad peak near 80 Å for Ni, Co and NiFe, demonstrating the importance of bulk rather than interfacial spin-dependent scattering, in contrast to Fe/Cr multilayers. The magnetoresistance decreases exponentially with increasing interlayer (Cu and Au) thickness, indicating that the magnetoresistance is due to the exchange of polarized electrons from one ferromagnetic layer to the other. The variation with Ag interlayer thickness is different for structural reasons.

Journal

• Journal of Applied Physics

  Journal of Applied Physics 69 (8), 4774-4779, 1991-04-15

  AIP Publishing

Keywords

• General Physics and Astronomy

Details

• CRID: 1361418518635736448
• NII Article ID: 80005931511
• NII Book ID: AA00693547
• DOI: 10.1063/1.348252
• ISSN: 10897550
• ISSN: 00218979
• ISSN: http://id.crossref.org/issn/00218979
• Web Site: https://pubs.aip.org/aip/jap/article-pdf/69/8/4774/18640586/4774_1_online.pdf
• Data Source:
  • Crossref
  • CiNii Articles