Acoustic-optical phonon scattering observed in the thermal conductivity of polydiacetylene single crystals
- 20 January 1985
- journal article
- Published by IOP Publishing in Journal of Physics C: Solid State Physics
- Vol. 18 (2) , 309-318
- https://doi.org/10.1088/0022-3719/18/2/010
Abstract
The steady-state thermal conductivity of polydiacetylene single crystals has been measured in the range 50 mK-50K. Below 1K the temperature dependence of the thermal conductivity approaches T3 as expected for single crystal whilst above 1K the conductivity is approximately proportional to T12/. The data above 1K have been interpreted by assuming that the acoustic phonons responsible for heat transport are scattered by low-energy optical modes associated with the motion of the massive polymer sidegroups. The five lowest optical modes observed by far-infrared absorption and inelastic neutron scattering are sufficient to explain the observed temperature dependence. A good fit to the data was achieved with each mode having an acoustic-optical coupling matrix element of 5 meV; the associated splitting of the phonon dispersion curves is estimated to be about 0.6 meV.Keywords
This publication has 17 references indexed in Scilit:
- Anomalous Thermal Conduction in Polydiacetylene Single CrystalsPhysical Review Letters, 1984
- Single crystal 2,4-hexadiynylene-bis (p-toluenesulfonate): Elastic properties and phase transitions in the monomer and polymerPhysica Status Solidi (a), 1983
- X-ray Study of the Incommensurate Phase of Bis-(p-toluene Sulfonate) of 2, 4-Hexadiyne-1, 6 Diol as a Function of Polymer ConversionMolecular Crystals and Liquid Crystals, 1981
- Heat capacity of a polydiacetylene single crystal from 3 to 300 KJournal of Polymer Science: Polymer Physics Edition, 1980
- Far infrared studies of the solid-state phase transition in bis(p-toluene sulphonate)diacetylene monomer and polymerChemical Physics, 1980
- Structure, luminescence and polymerization of a diacetylene crystal: 1,6-di-(n-carbazolyl)-2,4 hexadiin (DCH)Chemical Physics Letters, 1977
- The crystal structure of the low-temperature phase of poly[1,2-bis(p-tolylsulphonyloxymethylene)-1-buten-3-ynylene]Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1977
- Correlation between thermal expansion and optical band splitting in polydiacetylene-bis(toluenesulfonate) single crystalsChemical Physics Letters, 1976
- The solid‐state thermal polymerization of bis(p‐toluene sulphonate) of 2,4‐hexadiyne‐1,6‐diol. III. An ESR studyJournal of Polymer Science: Polymer Physics Edition, 1975
- Poly-[1,2-bis-(p-tolylsulfonyloxymethylen)-1-buten-3-inylen]Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1974