Degree Type

Dissertation

Date of Award

2017

Degree Name

Doctor of Philosophy

Department

Materials Science and Engineering

Major

Materials Science and Engineering

First Advisor

Steve W. Martin

Abstract

Interest in chalcogenide glasses has been growing for decades. Unlike oxide glasses, sulfide glasses have large anions and weaker bonding. This sacrifices high melting and glass transition temperatures (Tg) for increased infrared transparency. While most research has been focused on increasing the infrared transparency of these materials little has been done to maximize both infrared transparency and Tg, but a new set of chalcogenide glasses built around ionic bonding schemes have shown promise in optimizing both of these properties. One application demanding such properties is chemical sensors for remote sensing in new advanced small modular nuclear reactors (AdvSMNRs) to detect trace amounts of gaseous compounds inside of the reactor environment.

This work focuses on understanding mechanisms that maximize Tg, infrared transparency, and gamma radiation resistance of three series of ionic sulfide glasses in the xBaS + yLa2S3 + (1-x-y)GeS2 system. Glasses prepared by sealing and melting stoichiometric amounts of sulfide compounds together in silica ampoules at 1150 °C. These glasses achieve Tgs in excess of 550 °C, have transmission window that expands from 0.5-10 μm. In addition, glasses show minimal transmission, density, and refractive index change after 453 kGy gamma radiation dose. This allows for the detection of infrared active molecules in the infrared spectrum at elevated temperatures making these strong candidates for chemical sensors in reactor environments.

Copyright Owner

Joshua Raymond Roth

Language

en

File Format

application/pdf

File Size

104 pages

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