Date of Award
3-2024
Document Type
Dissertation
Degree Name
Ph.D.
Organizational Unit
College of Natural Science and Mathematics, Physics and Astronomy
First Advisor
Barry L. Zink
Second Advisor
Xin Fan
Third Advisor
Pavel Salev
Fourth Advisor
Michelle K. Knowles
Keywords
Spin hall effect, Spincaloritronics, Spintronics
Abstract
In this dissertation begin with an investigation of non-local spin transport in an amorphous germanium (a-Ge) sample via the inverse spin Hall effect (ISHE). In that study we show that commonly used techniques such as differential conductance and delta mode of a paired Keithley 6221/2182a for non-local resistance measurements can lead to false indicators of spin transport. Next, we turn out attention to a thickness dependent study in thermally-evaporated chromium (Cr) thin films on a bulk polycrystalline yttrium-iron-garnet (YIG) substrate. This project analyzed the spin transport in the Cr films versus thickness via the longitudinal spin Seebeck effect (LSSE). This research revealed a complex thickness dependence of the spin-to-charge conversion and LSSE voltages for the evaporated Cr that may be a consequence of strain in Cr and finite size effects. We continue to examine LSSE in thermallyevaporated Cr, but now under a temperature dependent study. The results reveal an enhancement in the evaporated Cr below 200 K, where the Cr thin film transitions from a mixed SDW antiferromagnetic state described by the combination of a antiferromagnetic commensurate SDW (CSDW) and paramagnetic incommensurate SDW (ISDW) to a full antiferromagnetic state where both CSDW and ISDW are antiferromagnetic. This is absent in sputtered Cr thin films deposited on similar YIG substrates. Finally, we explore the spin-flopped coupled lanthanum strontium ferrite (LSFO) lanthanum strontium manganite (LSMO) bilayer grown on a lanthanum strontium aluminate (LSAT) substrate. This research focuses on the possible control of magnetic moments using current pulses.
Copyright Date
3-2024
Copyright Statement / License for Reuse
All Rights Reserved.
Publication Statement
Copyright is held by the author. User is responsible for all copyright compliance.
Rights Holder
Sam M. Bleser
Provenance
Received from ProQuest
File Format
application/pdf
Language
English (eng)
Extent
183 pgs
File Size
16.3 MB
Recommended Citation
Bleser, Sam M., "The Interplay of Spin, Charge, and Heat: From Metal/Insulator Heterostructures to Perovskite Bilayers" (2024). Electronic Theses and Dissertations. 2371.
https://digitalcommons.du.edu/etd/2371
Discipline
Physics