Nanoscale magnetic characterization of tunneling magnetoresistance spin valve head by electron holography

Hyun Soon Park, Kei Hirata, Keiichi Yanagisawa, Yoichi Ishida, Tsuyoshi Matsuda, Daisuke Shindo, Akira Tonomura

    Research output: Contribution to journalArticlepeer-review

    5 Citations (Scopus)

    Abstract

    Nanostructured magnetic materials play an important role in increasing miniaturized devices. For the studies of their magnetic properties and behaviors, nanoscale imaging of magnetic field is indispensible. Here, using electron holography, the magnetization distribution of a TMR spin valve head of commercial design is investigated without and with a magnetic field applied. Characterized is the magnetic flux distribution in complex hetero-nanostructures by averaging the phase images and separating their component magnetic vectors and electric potentials. The magnetic flux densities of the NiFe (shield and 5 nm-free layers) and the CoPt (20 nm-bias layer) are estimated to be 1.0 T and 0.9 T, respectively. The changes in the magnetization distribution of the shield, bias, and free layers are visualized in situ for an applied field of 14 kOe. This study demonstrates the promise of electron holography for characterizing the magnetic properties of hetero-interfaces, nanostructures, and catalysts. Nanostructured magnetic materials play an important role in increasing miniaturized devices. For the studies of their magnetic properties and behaviors, nanoscale imaging of magnetic field is indispensible. Here, using electron holography, the magnetization distribution of a TMR spin valve head of commercial design is investigated without and with a magnetic field applied. Characterized is the magnetic flux distribution in complex hetero-nanostructures by averaging the phase images and separating their component magnetic vectors and electric potentials.

    Original languageEnglish
    Pages (from-to)3640-3646
    Number of pages7
    JournalSmall
    Volume8
    Issue number23
    DOIs
    Publication statusPublished - 2012 Dec 7

    Keywords

    • TMR spin valve head
    • hetero-interfaces
    • holography
    • magnetization distribution
    • nanoscale characterization

    ASJC Scopus subject areas

    • Biotechnology
    • Biomaterials
    • Chemistry(all)
    • Materials Science(all)

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