Award Date

5-1-2019

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Physics and Astronomy

First Committee Member

Ashkan Salamat

Second Committee Member

Qiang Zhu

Third Committee Member

Liping Wang

Fourth Committee Member

Jason Steffen

Fifth Committee Member

Pamela Burnley

Number of Pages

54

Abstract

Metastability of states can provide interesting properties that may not be readily accessible in a material’s ground state. Many materials show high levels of polymorphism, indicating a rich energy landscape and a potential for metastable states. Melt crystallization techniques provide a potential route to these states. We use a resistively heated diamond anvil cell (DAC) with fine control of a system’s pressure and temperature to explore these systems. Raman spectroscopy is used to track subtle structural changes across phase boundaries. Organic systems, such as glycine and aspirin, were our initial interest due to their high polymorphism and reported low melting temperatures; however, complications with these systems ultimately showed that they are not ideal candidates for this technique. Metallic systems with allowed Raman modes are better samples for this method. We successfully map the phase stability of β-tin under high pressure and temperature conditions using Raman spectroscopy.

Keywords

Aspirin; Glycine; High pressure; High temperature; Resistive heating; Tin

Disciplines

Condensed Matter Physics | Optics | Other Physics | Physics

Language

English


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