Local control of magnetic anisotropy
Abstract/Contents
- Abstract
- Investigating physical mechanisms to manipulate magnetic anisotropy is important for technological applications. We use a scanning superconducting quantum interference device (SQUID) microscope to image the response of micron-scale magnetism to externally controlled currents, voltages and strains. The first part of this thesis (chapters 2 and 3) focus on the physics behind devices and materials that could replace silicon transistors. Chapter 2 focuses on a proposal for a new magnetic memory device using spin transfer torque from the spin Hall effect to manipulate ferromagnetic insulators. Ultimately, this proposal did not prove to be fruitful because of diverging ferromagnetic damping at low temperatures and lacking studies on the spin transparency between the spin Hall metal and the magnetic insulator. Chapter 3 is about SQUID characterization of a composite multiferroic, which can be the basis for another magnetic memory proposal. These results proved to be inconclusive, and modeling these systems proved to be difficult because of the multi-domain behavior of these films. The second part of this thesis (chapters 4 and 5) focuses on how a common substrate, SrTiO$_3$ (STO) can profoundly affect electronic properties including transport and magnetism. Chapter 4 describes experiments on the conducting interface between band insulators LaAlO$_3$/STO. We examined magnetism in related compounds LaGaO$_3$/STO and NdGaO$_3$/STO, and found that ferromagnetic patches in those systems, like in LaAlO$_3$/STO was very sparse and nearly non-existent. In addition, we measured how electronic transport on a local scale changed with strain, and our results were inconclusive. Finally, Chapter 5 describes how magnetism in EuS, a ferromagnetic insulator that could be used to induce exotic phases like Majorana bound states or chiral edge states, is strongly coupled to the STO substrate. We explore how strain from the STO substrate could affect magnetic anisotropy. This thesis highlights the importance of temperature on controlling magnetic anisotropy for switching experiments and for constructing devices that require homogeneous magnetic exchange.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2017 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Rosenberg, Aaron J |
|---|---|
| Associated with | Stanford University, Department of Applied Physics. |
| Primary advisor | Moler, Kathryn A |
| Thesis advisor | Moler, Kathryn A |
| Thesis advisor | Goldhaber-Gordon, David, 1972- |
| Thesis advisor | Suzuki, Yuri, (Applied physicist) |
| Advisor | Goldhaber-Gordon, David, 1972- |
| Advisor | Suzuki, Yuri, (Applied physicist) |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Aaron J. Rosenberg. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2017. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2017 by Aaron Joshua Rosenberg
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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