Tunnel spin polarization versus energy for clean and doped Al2O3 barriers

B.G. Park, T. Banerjee, J.C. Lodder, R. Jansen

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    Abstract

    The variation of the tunnel spin-polarization (TSP) with energy is determined using a magnetic tunnel transistor, allowing quantification of the energy dependent TSP separately for both ferromagnet/insulator interfaces and direct correlation with the tunnel magnetoresistance (TMR) measured in the same device. The intrinsic TSP is reduced below the Fermi level, and more strongly so for tunneling into empty states above the Fermi level. For artificially doped barriers, the low bias TMR decreases due to defect-assisted tunneling. Yet, this mechanism becomes ineffective at large bias, where instead inelastic spin scattering causes a strong TMR decay.
    Original languageUndefined
    Pages (from-to)217206
    Number of pages4
    JournalPhysical review letters
    Volume99
    Issue number5
    DOIs
    Publication statusPublished - 20 Nov 2007

    Keywords

    • METIS-247021
    • IR-58276
    • EWI-12094

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