Title

Thermophysical Properties And Conduction Mechanisms In AsXSe1-X Chalcogenide Glasses Ranging From X = 0.2 To 0.5

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 examin e 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.

Publication Date

10-14-2016

Publication Title

Journal of Applied Physics

Volume

120

Issue

14

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1063/1.4962446

Socpus ID

84991713212 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84991713212

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