- Titel
- Magnetron sputtering of magnetic thin film materials for spintronics
- Zitierfähige Url:
- https://nbn-resolving.org/urn:nbn:de:bsz:14-qucosa2-947859
- Datum der Einreichung
- 06.06.2024
- Datum der Verteidigung
- 22.11.2024
- Abstract (EN)
- Spintronics explores the utilization of the electron spin in addition to the charge in solid-state devices, with the goal of enhancing functionality beyond conventional electronics. An essential component for many spintronic devices are magnetic thin film, and consequentially the fabrication of such films often marks the first step in the research of novel materials or towards their integration into applications. In this thesis, the film growth and the properties of two different magnetic thin film materials, grown by magnetron sputtering, are investigated. The first part of the thesis is focused on MnAl. This ferrimagnetic alloy features a high magnetocrystalline anisotropy, making it attractive for application as rare-earth free permanent magnet or in various spintronic applications as a perpendicular magnetic anisotropy (PMA) material. However, so far, the magnetothermal transport properties of MnAl, i.e. the anomalous Nernst effect (ANE), are still unknown. Here, we will report on the successful growth of MnAl thin films, and their magnetothermal transport properties. For the fabrication, MgO substrates with a Cr buffer layer were utilised, and several deposition parameter were optimised to achieve a chemically ordered, highly texturised MnAl. By magnetometry measurement as well as measurements of the anomalous Hall effect (AHE), we demonstrate the PMA and find magnetic properties comparable to other MnAl thin films. Finally, the magnetothermal transport properties, especially the ANE, are investigated. We find that the ANE features the signature of PMA, and the anomalous Nernst coefficient is comparable to other PMA materials. With that, we establish MnAl thin films as a potential candidate for spintronic or spincaloritronic applications. The second part of the thesis is centred around the ferrimagnetic insulator of aluminium substituted yttrium iron garnet (YAlIG). Magnetic garnets, in particular yttrium iron garnet (YIG), are widely used materials in spintronic or magnonic experiments. However, experiments at elevated temperatures around the Curie temperature have proven to be challenging. In the framework of this thesis, we aim to reduce the Curie temperature of YIG by substitution with Al. To this end, YAlIG thin films are prepared by radio frequency (rf) sputtering at room temperature in combination with an ex situ annealing step, and we demonstrate a high structural quality of the epitaxially grown thin film. The systematic reduction of the Curie temperature with increasing Al substitution is confirmed by magnetometry measurements. Upon characterisation by broadband ferromagnetic resonance, we find that the magnetic anisotropy is highly dependent on the substrate material, and a Gilbert damping comparable to other garnet thin films. Therefore, YAlIG thin films provide a material platform for spintronic and magnonic experiments across different magnetic phases.
- Verweis
- Link: https://arxiv.org/abs/2311.14498
Even-in-magnetic-field part of transverse resistivity as a probe of magnetic order - Detecting slow magnetization relaxation via magnetotransport measurements based on the current-reversal method
Link: https://arXiv:2405.14460 - Anomalous Nernst effect in perpendicularly magnetized τ-MnAl thin films
Link: https://pubs.aip.org/aip/adv/article/13/12/125227/2931962/Anomalous-Nernst-effect-in-perpendicularly - Aluminium substituted yttrium iron garnet thin films with reduced Curie temperature
DOI: 10.1103/PhysRevMaterials.7.094405 - Atomic layer deposition of yttrium iron garnet thin films
DOI: 10.1103/PhysRevMaterials.6.044411
Link: https://arxiv.org/abs/2311.14498 - Anisotropic magnetothermal transport in Co2MnGa thin films
DOI: 10.1103/PhysRevB.104.094406 - Freie Schlagwörter (EN)
- Magnetism, Thin films, Spintronics
- Klassifikation (DDC)
- 530
- Klassifikation (RVK)
- UP 7500
- GutachterIn
- Prof. Dr. Hans-Henning Klauss
- Prof. Dr. Günter Reiss
- Den akademischen Grad verleihende / prüfende Institution
- Technische Universität Dresden, Dresden
- Version / Begutachtungsstatus
- publizierte Version / Verlagsversion
- URN Qucosa
- urn:nbn:de:bsz:14-qucosa2-947859
- Veröffentlichungsdatum Qucosa
- 07.01.2025
- Dokumenttyp
- Dissertation
- Sprache des Dokumentes
- Englisch
- Lizenz / Rechtehinweis
CC BY 4.0