Sign reversal of spin polarization in Co/Ru/Al2O3/Co magnetic tunnel junctions

P.R. LeClair, B. Hoex, H. Wieldraaijer, J.T. Kohlhepp, H.J.M. Swagten, W.J.M. Jonge, de

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Utilizing ultrathin Ru interfacial layers in Co/Al2O3/Co tunnel junctions, we demonstrate that not only does the tunnel magnetoresistance decrease strongly as the Ru thickness increases as found for Cu or Cr interlayers, in contrast, even the sign of the apparent tunneling spin polarization may be changed. Further, the magnitude and sign of the apparent polarization is strongly dependent on applied voltage. The results are explained by a strong density-of-states modification at the (interdiffused) Co/Ru interface, consistent with theoretical calculations and experiments on Co/Ru metallic multilayers and Co-Ru alloys.
Original languageEnglish
Article number100406
Pages (from-to)100406-1/4
Number of pages4
JournalPhysical Review B
Issue number10
Publication statusPublished - 1 Jan 2001


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