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Description
Title: | A Study of Permalloy (Nickel(81)iron(19)) Nanoparticles as Possible Qubits |
Author(s): | Roos, Kimberly Lynn |
Doctoral Committee Chair(s): | Averback, Robert S. |
Department / Program: | Materials Science and Engineering |
Discipline: | Materials Science and Engineering |
Degree Granting Institution: | University of Illinois at Urbana-Champaign |
Degree: | Ph.D. |
Genre: | Dissertation |
Subject(s): | Engineering, Materials Science |
Abstract: | Permalloy nanoparticles are grown in a custom built inert gas condensation system with magnetron sputtering. By careful control of the processing parameters during nucleation, the nanoparticles can be grown with the desired diameter of 5 nm and a narrow size distribution with a standard deviation of ∼0.5 nm. As a result of the nucleation and growth process, the nanoparticles have a polycrystalline structure. Several heating methods are employed in an attempt to recrystallize the nanoparticles. In the end, ultrafast heating with a femtosecond laser system is used to form single crystal nanoparticles. The wavelength of the laser is strongly absorbed by the metal nanoparticles but not by the supporting substrate (a 50 nm thick S1O2 membrane). The ultra short pulse width of 175 fs also reduces the possibility of heat exchange between the particle and the substrate. This rapid heating causes melting of the particle and upon cooling, a single crystalline structure. These single crystal nanoparticles not only fulfill the requirements of the original project but also provide the first clear evidence that melting of metals can be achieved without significant material loss. Two distinct mechanisms of material loss are identified with separate thresholds. |
Issue Date: | 2006 |
Type: | Text |
Language: | English |
Description: | 104 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. |
URI: | http://hdl.handle.net/2142/82792 |
Other Identifier(s): | (MiAaPQ)AAI3242975 |
Date Available in IDEALS: | 2015-09-25 |
Date Deposited: | 2006 |
This item appears in the following Collection(s)
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Dissertations and Theses - Materials Science and Engineering
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Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois