1-D chalcogenide nanomaterials for electronics : phase-change memory and topological insulators

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Abstract/Contents

Abstract
Chalcogenides are ubiquitous in academia and industry. We focus on chalcogenides for phase-change memory and topological insulators. Phase change memory (PCM) utilizes the resistivity contrast between the crystalline and amorphous phases of certain chalcogenides to store information. Industry is making progress in PCM, which could someday compete with flash memory due to its superior scalability, fast switching and high endurance. In contrast, the field of topological insulators is very young. Topological insulators, bulk insulators with conductive surface states, have attracted great attention since their discovery five years ago. They have exotic properties and are exciting for both fundamental studies and potential applications. Our studies of chalcogenide nanomaterials for PCM and topological insulators provided new insights into these fascinating materials. We developed a method to switch PCM cells inside a transmission electron microscope (TEM), allowing direct correlation of electrical behavior with structural changes. Using this technique, we found that the electrical behavior of Ge2Sb2Te3 lateral phase-change cells depends strongly on the highly variable microstructure of the amorphous domain. In search of new PCM materials, we developed the VLS synthesis of GeTe and Sb2Te3 phase-change nanowires. In situ TEM observation of these nanowires revealed a new switching mechanism via the opening and closing of voids. We also synthesized single-crystalline topological insulator nanoribbons, whose large surface to bulk conduction ratio increases the relative contribution of the surface states. We successfully measured Aharonov-Bohm oscillations in the nanoribbons, thereby observing one of the first electrical signatures of the topological states in this material system.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2010
Issuance monographic
Language English

Creators/Contributors

Associated with Meister, Stefan
Associated with Stanford University, Department of Materials Science and Engineering
Primary advisor Cui, Yi, 1976-
Thesis advisor Cui, Yi, 1976-
Thesis advisor Goldhaber-Gordon, David, 1972-
Thesis advisor McIntyre, P. (Paul)
Advisor Goldhaber-Gordon, David, 1972-
Advisor McIntyre, P. (Paul)

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Stefan Meister.
Note Submitted to the Department of Materials Science and Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2010.
Location electronic resource

Access conditions

Copyright
© 2010 by Stefan Meister
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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