What question did this study set out to answer?

To determine whether four-phonon interactions and acoustic-optical phonon scattering account for the faster-than-linear temperature dependence of thermal resistivity in dielectric crystals at elevated temperatures.

June 15, 1977Physical review. B, Solid state

Thermal resistivity of die ectric crystals due to four-phonon processes and optical modes

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To determine whether four-phonon interactions and acoustic-optical phonon scattering account for the faster-than-linear temperature dependence of thermal resistivity in dielectric crystals at elevated temperatures.
Derived four-phonon interaction rates at high temperatures using the Grüneisen constant, its dilational derivative, quartic anharmonicities, and second-order cubic anharmonicities.
Calculated acoustic phonon relaxation rates arising from anharmonic interactions between two acoustic phonons and one optical phonon as a function of temperature and frequency.
The four-phonon relaxation rate scaled with the square of frequency and temperature but remained weaker than the three-phonon relaxation rate by at least a factor of 30 at 1000 K.
Scattering involving two acoustic phonons and one optical phonon exhibited magnitude and temperature dependence similar to three-acoustic-phonon processes, though it was forbidden at the lowest frequencies.
Neither four-phonon scattering nor optical phonon interactions quantitatively explained the supralinear increase of thermal resistance with temperature observed in dielectric crystals.

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Implication

Theoretical analysis reveals weak four-phonon and optical-mode contributions to high-temperature thermal resistivity in dielectric crystals, indicating other mechanisms drive nonlinear resistance.

Cite This Study

Ecsedy et al. (1977) studied this question.

synapsesocial.com/papers/6a762610fa1990f79e6142c3 https://doi.org/10.1103/physrevb.15.5957

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Implication

Theoretical analysis reveals weak four-phonon and optical-mode contributions to high-temperature thermal resistivity in dielectric crystals, indicating other mechanisms drive nonlinear resistance.

Thermal resistivity of die ectric crystals due to four-phonon processes and optical modes

Key Points

Discussion

Implication

Cite This Study

Thermal resistivity of die ectric crystals due to four-phonon processes and optical modes

Key Points

Discussion

Implication

Cite This Study

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