Master's Thesis
Spin wave excitation and propagation in magnonic crystals prepared by focused ion beam direct writing
Final Thesis 9.83 MBAuthor of thesis: Ing. Viola Křižáková
Acad. year: 2017/2018
Supervisor: Ing. Michal Urbánek, Ph.D.
Reviewer: Mgr. Kamil Olejník, Ph.D.
Abstract:Paramagnetic Ni-stabilized fcc Fe thin films epitaxially grown on Cu(100) are known for their capability to undergo ion-beam-induced phase transformation into ferromagnetic bcc phase. To bring these metastable films closer to the application, a Cu(100) substrate can be further substituted by Si(100) with a Cu(100) buffer layer. With the use of a focused ion beam, magnetic properties of the films can be locally tailored and modulated. Moreover, this alternative approach to the preparation of media suitable for spin-wave guidance provides patterning possibilities unattainable by conventional lithography techniques. Magnetic structures prepared in this way are studied by all-electrical spin-wave spectroscopy. This thesis covers the entire process from the metastable thin film growth, through the patterning, to structural studies and static and dynamic magnetic characterization. A broadband ferromagnetic resonance and propagating spin wave spectroscopy experiments are performed on focused-ion-beam-transformed continuous layers and microstructures. Microscale coplanar waveguides are used for inductive excitation and detection of spin waves with defined wavevectors. Magnetic properties such as saturation magnetization and damping are extracted from the ferromagnetic resonance measurements and characteristics of the propagating modes such as spin-wave decay length or group velocity are studied and compared with common ferromagnetic materials.
magnonics, spin wave excitation and detection, ferromagnetic resonance, propagating spin-wave spectroscopy, metastable thin films, magnetic phase transformation
Date of defence
18.06.2018
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
Jak fyzikálně funguje buzení spinových vln pomocí vlnovodů? Mohla byste prosím podat podrobnější výklad k obrázkům uvedeným na straně 27? Jaká je hloubka pronikání elektronů při použití metody LEED?
Language of thesis
English
Faculty
Department
Study programme
Applied Sciences in Engineering (M2A-P)
Field of study
Physical Engineering and Nanotechnology (M-FIN)
Composition of Committee
prof. RNDr. Tomáš Šikola, CSc. (předseda)
prof. RNDr. Miroslav Liška, DrSc. (místopředseda)
prof. RNDr. Bohumila Lencová, CSc. (člen)
prof. RNDr. Jiří Komrska, CSc. (člen)
prof. RNDr. Petr Dub, CSc. (člen)
prof. RNDr. Radim Chmelík, Ph.D. (člen)
prof. RNDr. Jiří Spousta, Ph.D. (člen)
prof. RNDr. Eduard Schmidt, CSc. (člen)
prof. RNDr. Pavel Zemánek, Ph.D. (člen)
RNDr. Antonín Fejfar, CSc. (člen)
doc. Ing. Radek Kalousek, Ph.D. (člen)
Supervisor’s report
Ing. Michal Urbánek, Ph.D.
Grade proposed by supervisor: A
Reviewer’s report
Mgr. Kamil Olejník, Ph.D.
Grade proposed by reviewer: A