The study of micromagnetics both yields important applications, like computer hard disks which enabled the creation of the internet, and continues to reveal surprising phenomena and open new scientific questions, like the search for the magnetic hopfion , a 3D topological soliton. An important trend in micromagnetics research is studying topological magnetic structures, with particular interest in their potential as nanoscale information carriers. For instance, the magnetic skyrmion, a topological soliton, can be as small as 1 nm and may enable new forms of data storage and computing due to its high mobility and topological protection –. However, this is pushing the resolution of imaging techniques. One of the few methods that can image magnetic materials at this scale is transmission electron microscopy (TEM).
Here I will present the use of transmission electron microscopy to study nanoscale topological magnetic domains under an applied magnetic field in a novel thin film material in which both the dipole interaction and the Dzyaloshinskii-Moriya interaction determine the magnetic structure . I demonstrate the first application of scanning TEM holography, a recently developed phase measurement technique, implemented with a diffraction grating to image magnetic materials. Lastly, I propose how this technique could be used to perform the first experimental observation of a magnetic hopfion and show initial results.
|Advisor:||McMorran, Benjamin J., Aleman, Benjamín|
|Commitee:||Parthasarathy, Raghuveer, Santala, Melissa, Lonergon, Mark|
|School:||University of Oregon|
|Department:||Department of Physics|
|School Location:||United States -- Oregon|
|Source:||DAI-B 82/9(E), Dissertation Abstracts International|
|Keywords:||Interferometric Electron Microscopy, Holography, Transmission Electron Microscopy, Micromagnetics, Nanomagnetic imaging|
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