In situ observations of domain structures and magnetic flux distributions in Mn-Zn and Ni-Zn ferrites by Lorentz microscopy and electron holography

Takehiro Kasahara, Daisuke Shindo, Hideyuki Yoshikawa, Takafumi Sato, Koichi Kondo

    Research output: Contribution to journalArticlepeer-review

    10 Citations (Scopus)

    Abstract

    Domain structures and magnetic flux distributions in Mn-Zn and Ni-Zn ferrites are investigated by in situ observations with Lorentz microscopy and electron holography. In situ Lorentz microscopic observation with the magnetic field applied reveals that the domain walls in Mn-Zn ferrite move easily across the grain boundary. On the other hand, each grain of Ni-Zn ferrite is magnetized by domain wall motion inside the grain. By taking a series of holograms with adjustment of the optical axis and astigmatism while the magnetic field is applied, we succeeded in observing the change in magnetic flux distribution quantitatively. Eventually, it is clarified that magnetization rotation does not take place in the magnetization process of Ni-Zn ferrite. The domain wall widths δ in Mn-Zn and Ni-Zn ferrites are evaluated to be 73 and 58 nm, respectively. Furthermore, through direct observation of the domain structure in Ni-Cu-Zn ferrite with Lorentz microscopy, it is found that the grains with size below 1.5 μm diameter are single domain.

    Original languageEnglish
    Pages (from-to)7-16
    Number of pages10
    JournalJournal of Electron Microscopy
    Volume56
    Issue number1
    DOIs
    Publication statusPublished - 2007 Jan

    Keywords

    • Domain wall motion
    • Electron holography
    • Ferrite
    • In situ observation
    • Lorentz microscopy
    • Magnetic flux

    ASJC Scopus subject areas

    • Instrumentation

    Fingerprint

    Dive into the research topics of 'In situ observations of domain structures and magnetic flux distributions in Mn-Zn and Ni-Zn ferrites by Lorentz microscopy and electron holography'. Together they form a unique fingerprint.

    Cite this