Abstract

The thermal conductivities along the basal and hexagonal directions of α-quartz silica, the low-temperature form of crystalline SiO2, are predicted from the solution of the Boltzmann transport equation combined with the van Beest, Kramer, and van Santen potential for the temperature up to 900 K and the pressure as high as 4 GPa. The thermal conductivities at atmospheric pressure, which show a negative and nonlinear dependence on temperature, are in reasonable agreement with the experimental data. The influence of pressure on thermal conductivity is positive and linear. The pressure (P) and temperature (T) dependences of the thermal conductivity (λ) in basal and hexagonal directions are fitted to a function of the form λ = (b + cP) Ta. The thermal conductivity, influenced by temperature and pressure, is analyzed based on phonon properties, including spectral thermal conductivity, dispersion relation, phonon density of states, phonon lifetime, and phonon probability density distribution function.

Department(s)

Physics

Research Center/Lab(s)

Center for High Performance Computing Research

Comments

The support from the National Natural Science Foundation of China (NNSFC) (Grant No. 51720105007) is greatly acknowledged.

Keywords and Phrases

Atmospheric pressure; Atmospheric temperature; Boltzmann equation; Distribution functions; Phonons; Probability density function; Quartz, Boltzmann transport equation; Dispersion relations; High-pressure and temperatures; Lattice thermal conductivity; Nonlinear dependence; Phonon density of state; Probability density distribution; Temperature and pressures, Thermal conductivity

International Standard Serial Number (ISSN)

0021-8979; 1089-7550

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2019 The Authors, All rights reserved.

Publication Date

01 Dec 2019

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Physics Commons

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