Bachelor's Thesis
Magneto-optical imaging and analysis of magnetic domain microstructures
Final Thesis 10.7 MBAuthor of thesis: Ing. Tomáš Molnár
Acad. year: 2020/2021
Supervisor: M.Sc. Jon Ander Arregi Uribeetxebarria, Ph.D.
Reviewer: Ing. Ondřej Wojewoda, Ph.D.
Abstract:Magneto-optical effects are associated with the interaction of polarized light with magnetized media. Although discovered nearly two centuries ago, magneto-optics is a widely utilized tool for magnetic characterization due to its high sensitivity and versatility. For example, it enables visualization of magnetic domain structures in microscale magnetic systems via wide-field magneto-optical microscopy. The majority of research on this topic has employed linear effects in magnetization to image domains in ferromagnetic materials, where one measures an optical contrast for regions with opposite magnetization orientations. It has been recently shown that even antiferromagnetic materials can be studied using quadratic magneto-optical effects (Voigt effect), making it possible to visualize regions with different spin axis orientations. In this work, we perform a fundamental magneto-optical microscopy study of magnetic thin film and microstructure systems using linear and quadratic effects. Consequently, the microscale magnetization configuration of continuous and patterned magnetic thin films is interpreted via the image processing strategy developed in this thesis, leading to quantitative vector magnetometry. Moreover, the coexistence of the ferro- and antiferromagnetic phase domains in FeRh films was investigated using optical and magneto-optical microscopy.
vectorial magnetometry, magnetic domains, magneto-optics, Kerr effect, Voigt effect, FeRh, permalloy, phase transition
Date of defence
17.06.2021
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
Po otázkách oponenta bylo diskutováno: vliv historie externího pole na stav magnetizace Student na otázku odpověděl. Rozprava proběhla v angličtině.
Language of thesis
English
Faculty
Department
Study programme
Applied Sciences in Engineering (B3A-P)
Field of study
Physical Engineering and Nanotechnology (B-FIN)
Composition of Committee
prof. RNDr. Tomáš Šikola, CSc. (předseda)
prof. RNDr. Miroslav Liška, DrSc. (místopředseda)
prof. RNDr. Bohumila Lencová, CSc. (člen)
doc. Ing. Stanislav Průša, Ph.D. (člen)
prof. RNDr. Petr Dub, CSc. (člen)
prof. RNDr. Radim Chmelík, Ph.D. (člen)
prof. RNDr. Jiří Spousta, Ph.D. (člen)
doc. Ing. Radek Kalousek, Ph.D. (člen)
RNDr. Antonín Fejfar, CSc. (člen)
Supervisor’s report
M.Sc. Jon Ander Arregi Uribeetxebarria, Ph.D.
Grade proposed by supervisor: A
Reviewer’s report
Ing. Ondřej Wojewoda, Ph.D.
Grade proposed by reviewer: A