A new twist on organic spintronics; controlling transport in organic sandwich devices using fringe fields from ferromagnetic films

Markus Wohlgenannt, Michael E. Flatté, Nicholas J. Harmon, Fujian Wang, Andrew D. Kent, Ferran Macià, Peter Fischer, Mi Young Im

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    Random, spatially uncorrelated nuclear-hyperfine fields in organic materials dramatically affect electronic transport properties such as electrical conductivity, photoconductivity, and electroluminescence. Competition between spin-dynamics due to these spatially uncorrelated fields and an applied magnetic field leads to large magnetoresistance, even at room temperature where the thermodynamic influences of the resulting nuclear and electronic Zeeman splittings are negligible. Here, we discuss a new method of controlling the electrical conductivity of an organic film at room temperature, using the spatially varying magnetic fringe fields of a magnetically unsaturated ferromagnet. Fringe-field magnetoresistance has a magnitude of several percent, and is hysteretic and anisotropic. This new method of control is sensitive to even remanent magnetic states, leading to different conductivity values in the absence of an applied field. The fringe field effects are insensitive to the ferromagnetic film's thickness (and therefore the fringe field magnitude) but sensitive to the magnetic domain's correlation length. This points at fringe-field gradients as an important ingredient of this mechanism. We develop a model based on fringe-field induced polaron-pair spin-dynamics that successfully describes several key features of the experimental fringe-field magnetoresistance.

    Original languageEnglish (US)
    Title of host publicationSpintronics VI
    Volume8813
    DOIs
    StatePublished - 2013
    Event6th Spintronics Symposium - San Diego, CA, United States
    Duration: Aug 25 2013Aug 29 2013

    Other

    Other6th Spintronics Symposium
    CountryUnited States
    CitySan Diego, CA
    Period8/25/138/29/13

    Fingerprint

    Spintronics
    Magnetoelectronics
    ferromagnetic films
    Sandwich
    Magnetoresistance
    spin dynamics
    Twist
    Spin dynamics
    electrical resistivity
    room temperature
    magnetic domains
    organic materials
    electronics
    ingredients
    photoconductivity
    electroluminescence
    Gene Conversion
    Magnetic domains
    film thickness
    transport properties

    Keywords

    • fringe-field magnetoresistance
    • organic magnetoresistance
    • room-temperature magnetoresistance

    ASJC Scopus subject areas

    • Applied Mathematics
    • Computer Science Applications
    • Electrical and Electronic Engineering
    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics

    Cite this

    Wohlgenannt, M., Flatté, M. E., Harmon, N. J., Wang, F., Kent, A. D., Macià, F., ... Im, M. Y. (2013). A new twist on organic spintronics; controlling transport in organic sandwich devices using fringe fields from ferromagnetic films. In Spintronics VI (Vol. 8813). [88130O] https://doi.org/10.1117/12.2024602

    A new twist on organic spintronics; controlling transport in organic sandwich devices using fringe fields from ferromagnetic films. / Wohlgenannt, Markus; Flatté, Michael E.; Harmon, Nicholas J.; Wang, Fujian; Kent, Andrew D.; Macià, Ferran; Fischer, Peter; Im, Mi Young.

    Spintronics VI. Vol. 8813 2013. 88130O.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Wohlgenannt, M, Flatté, ME, Harmon, NJ, Wang, F, Kent, AD, Macià, F, Fischer, P & Im, MY 2013, A new twist on organic spintronics; controlling transport in organic sandwich devices using fringe fields from ferromagnetic films. in Spintronics VI. vol. 8813, 88130O, 6th Spintronics Symposium, San Diego, CA, United States, 8/25/13. https://doi.org/10.1117/12.2024602
    Wohlgenannt M, Flatté ME, Harmon NJ, Wang F, Kent AD, Macià F et al. A new twist on organic spintronics; controlling transport in organic sandwich devices using fringe fields from ferromagnetic films. In Spintronics VI. Vol. 8813. 2013. 88130O https://doi.org/10.1117/12.2024602
    Wohlgenannt, Markus ; Flatté, Michael E. ; Harmon, Nicholas J. ; Wang, Fujian ; Kent, Andrew D. ; Macià, Ferran ; Fischer, Peter ; Im, Mi Young. / A new twist on organic spintronics; controlling transport in organic sandwich devices using fringe fields from ferromagnetic films. Spintronics VI. Vol. 8813 2013.
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