Thermoactivated heat transfer mechanism in molecular crystals: Thermal conductivity of benzophenone single crystals

Autor: A. Jeżowski, M. A. Strzhemechny, A. I. Krivchikov, O. S. Pyshkin, O. O. Romantsova, O. A. Korolyuk, D. I. Zloba, Yu. V. Horbatenko, A. Filatova
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: AIP Advances, Vol 9, Iss 1, Pp 015121-015121-7 (2019)
Druh dokumentu: article
ISSN: 2158-3226
DOI: 10.1063/1.5038676
Popis: Thermal conductivities of two benzophenone single crystals have been measured at temperatures from 4.7 to 270 K. The experimental data for both are consistent for temperatures above 15 K. The thermal conductivity of benzophenone can be represented as a sum of two contributions: κ1 + κTA where κ1 is due to the standard phonon mechanisms accepted for ordered crystals and κTA takes into account the heat flow due to intermolecular hopping of thermally activated intramolecular vibrational modes. The thermal activation contribution in unsubstituted benzophenone is substantially smaller when compared to that in any of the two para-bromobenzophenone polymorphs studied previously. Unlike in the 4-bromobenzophenone crystals, the microscopic agent responsible for intramolecular excitation(s) was not determined. The characteristic intramolecular excitation energy was evaluated to be 220 K, about three times less compared to 4-bromobenzophenone.
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