Model-based magnetization retrieval from holographic phase images
Model-based magnetization retrieval from holographic phase images
Röder, F.; Vogel, K.; Wolf, D.; Hellwig, O.; Wee, S. H.; Wicht, S.; Rellinghaus, B.
The phase shift of the electron wave is a useful measure for the projected magnetic flux density of magnetic objects at the nanometer scale. More important for materials science, however, is the knowledge about the magnetization in a magnetic nano-structure. As demonstrated here, a dominating presence of stray fields prohibits a direct interpretation of the phase in terms of magnetization modulus and direction. We therefore present a model-based approach for retrieving the magnetization by considering the projected shape of the nano-structure and assuming a homogeneous magnetization therein. We apply this method to FePt nano-islands epitaxially grown on a SrTiO3 substrate, which indicates an inclination of their magnetization direction relative to the structural easy magnetic [001] axis. By means of this real-world example, we discuss prospects and limits of this approach.
Keywords: off-axis electron holography; magnetic imaging; FePt nano-structured film
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Ultramicroscopy 176(2017), 177-187
DOI: 10.1016/j.ultramic.2016.11.003
Cited 1 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-24568