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Study of magnetoelastic coupling in multiferroic heterostructures
Piotr Graczyk
Abstract
This work contains of three aims. First, the influence of spontaneous strain of bulk ferroelastic crystal onto magnetization of ferromagnetic thin film is showed experimentally by SQUID magnetometry. I showed a significant change in a thin NiFe film magnetization as a consequence of magnetoelastic coupling with a ferroelastic LiCsSO4 and KH2PO4 substrate. The results that are quantitatively consistent with the experimental data were obtained assuming the micromagnetic model. The magnetic domains in the NiFe were found by Kerr microscopy to strictly mimic the pattern of ferroelastic domains. This effect was quantitatively described in terms of a Stoner-Wohlfarth model, which permitted an estimation of the magnetostriction constant and the evolution of the magnetic easy axis in the film. Secondly, it is showed that Gd2(MoO4)3 substrate changed the frequency of magnetostatic surface spin wave in NiFe thin film. I compared the experimental values of this change with theoretical predictions using micromagnetic calculations and dispersion relations for spin waves. Such ferroelastic - ferromagnetic structure can be applied in the future, for example, to electrically tune the frequency of a spin wave, what may be useful in rapidly developing magnonic technology. For this purpose it is necessary to obtain high quality thin films of gadolinium molybdate, which was the last goal of this work. GMO thin films were deposited onto different substrates by pulsed laser deposition technique. High-quality, epitaxial α’-Gd2(MoO4)3 films of tetragonal defect scheelite type structure were obtained.- Record ID
- UAMae8273a2f7f34bda9efb637b2dd5863c
- Diploma type
- Doctor of Philosophy
- Author
- Piotr Graczyk (SNŚ/WyF/DoNP) Piotr Graczyk
- Title in Polish
- Badanie sprzężeń magnetosprężystych w multiferroikach heterostrukturalnych
- Title in English
- Study of magnetoelastic coupling in multiferroic heterostructures
- Language
- pl Polish
- Certifying Unit
- Faculty of Physics (SNŚ/WyF/FoP)
- Discipline
- physics / (physical sciences domain) / (physical sciences)
- Scientific discipline (2.0)
- Defense Date
- 06-09-2016
- End date
- 06-09-2016
- Supervisor
- URL
- http://hdl.handle.net/10593/14888 opening in a new tab
- Keywords in English
- multiferroics, thin films, magnetostriction, magnetism
- Abstract in English
- This work contains of three aims. First, the influence of spontaneous strain of bulk ferroelastic crystal onto magnetization of ferromagnetic thin film is showed experimentally by SQUID magnetometry. I showed a significant change in a thin NiFe film magnetization as a consequence of magnetoelastic coupling with a ferroelastic LiCsSO4 and KH2PO4 substrate. The results that are quantitatively consistent with the experimental data were obtained assuming the micromagnetic model. The magnetic domains in the NiFe were found by Kerr microscopy to strictly mimic the pattern of ferroelastic domains. This effect was quantitatively described in terms of a Stoner-Wohlfarth model, which permitted an estimation of the magnetostriction constant and the evolution of the magnetic easy axis in the film. Secondly, it is showed that Gd2(MoO4)3 substrate changed the frequency of magnetostatic surface spin wave in NiFe thin film. I compared the experimental values of this change with theoretical predictions using micromagnetic calculations and dispersion relations for spin waves. Such ferroelastic - ferromagnetic structure can be applied in the future, for example, to electrically tune the frequency of a spin wave, what may be useful in rapidly developing magnonic technology. For this purpose it is necessary to obtain high quality thin films of gadolinium molybdate, which was the last goal of this work. GMO thin films were deposited onto different substrates by pulsed laser deposition technique. High-quality, epitaxial α’-Gd2(MoO4)3 films of tetragonal defect scheelite type structure were obtained.
- Thesis file
- Uniform Resource Identifier
- https://researchportal.amu.edu.pl/info/phd/UAMae8273a2f7f34bda9efb637b2dd5863c/
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