Abstract

The arsenic (As) to selenium (Se) ratio in AsxSe1-x glasses ranging from x = 0.2 to 0.5 was varied in order to examine the effect of chemical and topological ordering on the glass' thermal transport behavior. The fundamental thermal properties of glass transition temperature (Tg), thermal conductivity (k), and heat capacity (cp) were experimentally measured using differential scanning calorimetry, transient plane source method, and ultrasonic testing. Based on topological constraint theory, inflections in Tg and k were found at the structural coordination number «r» of 2.4, whereas a slight increase in heat capacity (cp) with increasing «r» was observed. A maximum in total thermal conductivity of 0.232 W/m·K was measured for the composition with x = 0.4, which corresponds to the stoichiometric As2Se3. Gas kinetic theory was used to derive an expression for the photon (kp) portion of thermal conductivity, which was calculated by measurements of the glass' absorption coefficient (α) and refractive index (n). Models based on Debye theory were used to derive expressions for specific heat (cv) and the lattice (kl) portion of thermal conductivity. The maximum value for kp was 0.173 W/m·K for the composition with x = 0.2, and a minimum value of 0.144 W/m·K was measured for the composition with x = 0.4. Photonic conduction was found to be the carrier mechanisms in all compositions, comprising 60% to 95% of the measured total thermal conductivity.

Department(s)

Materials Science and Engineering

Comments

U.S. Department of Energy, Grant DE-EE0005327

International Standard Serial Number (ISSN)

1089-7550; 0021-8979

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2023 American Institute of Physics, All rights reserved.

Publication Date

14 Oct 2016

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