Cornell University
Library
Cornell UniversityLibrary

eCommons

Help
Log In(current)
  1. Home
  2. Cornell University Graduate School
  3. Cornell Theses and Dissertations
  4. Critical Current Enhancement In Magnetic Spin-Transfer Nano-Devices Through Doping With The Rare Earth Terbium

Critical Current Enhancement In Magnetic Spin-Transfer Nano-Devices Through Doping With The Rare Earth Terbium

File(s)
emr28.pdf (9.18 MB)
Permanent Link(s)
https://hdl.handle.net/1813/31026
Collections
Cornell Theses and Dissertations
Author
Ryan, Eric
Abstract

In this thesis, we fabricate magnetic nanopillars and dramatically enhance their damping through terbium doping in order to suppress the various spin-transfer effects, to the potential benefit of magnetic hard drive read head technology. This enhancement is much stronger at lower temperatures, and we can understand the 1/T temperature dependence observed through the application of established theory from the iron garnets. We also show that terbium doping can address technological problems with hard drive read heads. In particular, by inhibiting the microwave noise until a higher turn-on current is reached, without compromising the ability of the device to switch with reasonable power in times scales as short as 1 nsec, terbium-doped structures point the way forward for future designs. Finally, we make direct FMR measurements of the Gilbert phenomenological damping parameter at the center of these effects, and these measurements also suggest cobalt-iron alloys as systems for potential follow-up work.

Date Issued
2012-08-20
Keywords
spin-transfer
•
terbium
•
magnetic
•
hard drive read head
•
nanopillar
•
damping
•
temperature
•
doping
Committee Chair
Buhrman, Robert A
Committee Member
Van Dover, Robert B.
McEuen, Paul L.
Degree Discipline
Applied Physics
Degree Name
Ph. D., Applied Physics
Degree Level
Doctor of Philosophy
Type
dissertation or thesis

Site Statistics | Help

About eCommons | Policies | Terms of use | Contact Us

copyright © 2002-2026 Cornell University Library | Privacy | Web Accessibility Assistance